50278 + Interview Questions in Physics

1.	What does generally the load resistance signify in half wave rectifier circuit diagram?
Answer» What does generally the load resistance signify in half wave rectifier circuit diagram?

Discussion

2.	Electric field is always directed from positive to negative. While dipole moment is always directed from negative to positive. So, it seems that dipole moment and electric field should always be in opposite directions. But in questions we come across that dipole moment is inclined at some angle to the direction of electric field. Why?
Answer» Electric field is always directed from positive to negative. While dipole moment is always directed from negative to positive. So, it seems that dipole moment and electric field should always be in opposite directions. But in questions we come across that dipole moment is inclined at some angle to the direction of electric field. Why?

Discussion

3.	A block A kept on an inclined surface just begins to slide if the inclination is 30∘. The block is replaced by another block B and it is found that it just begins to slide if the inclination is 40∘.
Answer» A block A kept on an inclined surface just begins to slide if the inclination is $30^{\circ}$ . The block is replaced by another block B and it is found that it just begins to slide if the inclination is $40^{\circ}$ .

Discussion

4.	The figure shows a circular wire - loop of radius a, carrying a current i, placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.
Answer» The figure shows a circular wire - loop of radius a, carrying a current i, placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.

4.

The figure shows a circular wire - loop of radius a, carrying a current i, placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.

Answer»

The figure shows a circular wire - loop of radius a, carrying a current i, placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.

Discussion

5.	Two magnets A and B are identical and these are arranged as shown in the figure. Their length is negligible in comparison to the separation between them. A magnetic needle is placed between the magnets at point P which gets deflected through an angle under the influence of magnets. The ratio of distance d1 and d2 will be
Answer» Two magnets A and B are identical and these are arranged as shown in the figure. Their length is negligible in comparison to the separation between them. A magnetic needle is placed between the magnets at point P which gets deflected through an angle under the influence of magnets. The ratio of distance $d_{1}$ and $d_{2}$ will be

Discussion

6.	A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then
Answer» A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then

Discussion

7.	One end of a spring of natural length h and spring constant k is fixed at the ground and the other is fitted with a smooth ring of mass m which is allowed to slide on a horizontal rod fixed at a height h (figure 8-E13). Initially, the spring makes an angle of 37∘ with the vertical when the system is released from rest. Find the speed of the ring when the spring becomes vertical.
Answer» One end of a spring of natural length h and spring constant k is fixed at the ground and the other is fitted with a smooth ring of mass m which is allowed to slide on a horizontal rod fixed at a height h (figure 8-E13). Initially, the spring makes an angle of $37^{\circ}$ with the vertical when the system is released from rest. Find the speed of the ring when the spring becomes vertical.

7.

One end of a spring of natural length h and spring constant k is fixed at the ground and the other is fitted with a smooth ring of mass m which is allowed to slide on a horizontal rod fixed at a height h (figure 8-E13). Initially, the spring makes an angle of 37∘ with the vertical when the system is released from rest. Find the speed of the ring when the spring becomes vertical.

Answer»

One end of a spring of natural length h and spring constant k is fixed at the ground and the other is fitted with a smooth ring of mass m which is allowed to slide on a horizontal rod fixed at a height h (figure 8-E13). Initially, the spring makes an angle of $37^{\circ}$ with the vertical when the system is released from rest. Find the speed of the ring when the spring becomes vertical.

Discussion

8.	A hollow spherical body of inner and outer radii 6 cm and 8 cm respectively floats half-submerged in water. Find the density of the material of the sphere.
Answer» A hollow spherical body of inner and outer radii 6 cm and 8 cm respectively floats half-submerged in water. Find the density of the material of the sphere.

Discussion

9.	A constant torque of 31.4 Nm is exerted on a pivoted wheel. If angular acceleration of wheel is 4π rads−2, then the moment of inertia of wheel is nearly equal to
Answer» A constant torque of $31.4 N m$ is exerted on a pivoted wheel. If angular acceleration of wheel is $4 π r a d s^{- 2}$ , then the moment of inertia of wheel is nearly equal to

Discussion

10.	A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration →a of magnitude 2 m/s2. Position vector →r locates him relative to the rotation axis. What is the magnitude of →r ? What is the direction of →r when →a is directed due east?
Answer» A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration $\to a$ of magnitude 2 m/s². Position vector $\to r$ locates him relative to the rotation axis. What is the magnitude of $\to r$ ? What is the direction of $\to r$ when $\to a$ is directed due east?

10.

A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration →a of magnitude 2 m/s2. Position vector →r locates him relative to the rotation axis. What is the magnitude of →r ? What is the direction of →r when →a is directed due east?

Answer»

A carnival merry-go-round rotates about a vertical axis at a constant rate. A man standing on the edge has a constant speed of 3 m/s and a centripetal acceleration $\to a$ of magnitude 2 m/s². Position vector $\to r$ locates him relative to the rotation axis.

What is the magnitude of $\to r$ ? What is the direction of $\to r$ when $\to a$ is directed due east?

Discussion

11.	A particle of mass m is released from point A on smooth fixed circular track as shown. If the particle is released from rest at t = 0, then variation of normal reaction N with (θ) angular displacement from initial position is
Answer» A particle of mass m is released from point A on smooth fixed circular track as shown. If the particle is released from rest at t = 0, then variation of normal reaction N with $(θ)$ angular displacement from initial position is

11.

A particle of mass m is released from point A on smooth fixed circular track as shown. If the particle is released from rest at t = 0, then variation of normal reaction N with (θ) angular displacement from initial position is

Answer»

A particle of mass m is released from point A on smooth fixed circular track as shown. If the particle is released from rest at t = 0, then variation of normal reaction N with $(θ)$ angular displacement from initial position is

Discussion

12.	The emissivity of tungsten is approximately 0.35. A tungsten sphere having 1 cm radius is suspended within a large evacuated enclosure whose walls are at 300 K. Find the power input required to maintain the sphere at a temperature of 3000 K if heat conduction along the support is neglected. σ=5.67×10−8 SI units.
Answer» The emissivity of tungsten is approximately $0.35$ . A tungsten sphere having $1 cm$ radius is suspended within a large evacuated enclosure whose walls are at $300 K$ . Find the power input required to maintain the sphere at a temperature of $3000 K$ if heat conduction along the support is neglected. $σ = 5.67 \times 10^{- 8} SI units$ .

Discussion

13.	Water- mirror system is shown in figure. A point object P is also marked. The radii of curriature of mirror is 120 cm. Two images of object P are considered one by direct reflection from water surface and other by refraction at water surface-reflection at mirror-refraction at water surface. The separation between two images isRefractive index of water is 48/3
Answer» Water- mirror system is shown in figure. A point object P is also marked. The radii of curriature of mirror is 120 cm. Two images of object P are considered one by direct reflection from water surface and other by refraction at water surface-reflection at mirror-refraction at water surface. The separation between two images is Refractive index of water is 48/3

13.

Water- mirror system is shown in figure. A point object P is also marked. The radii of curriature of mirror is 120 cm. Two images of object P are considered one by direct reflection from water surface and other by refraction at water surface-reflection at mirror-refraction at water surface. The separation between two images isRefractive index of water is 48/3

Answer»

Water- mirror system is shown in figure. A point object P is also marked. The radii of curriature of mirror is 120 cm. Two images of object P are considered one by direct reflection from water surface and other by refraction at water surface-reflection at mirror-refraction at water surface. The separation between two images is

Refractive index of water is 48/3

Discussion

14.	In the circuit, initially switch S has been open for a long time. It is then closed for a long time. The charge on the capacitor (in μC) changes by an amount of Here, C=30 μF,E1=1 V,E2=3 V,R1=0.2 Ω,R2=0.4 Ω.
Answer» In the circuit, initially switch $S$ has been open for a long time. It is then closed for a long time. The charge on the capacitor (in $μ C$ ) changes by an amount of Here, $C = 30 μ F, E_{1} = 1 V, E_{2} = 3 V, R_{1} = 0.2 Ω, R_{2} = 0.4 Ω$ .

Discussion

15.	A 5 kg block is pushed along a floor by a constant applied force that is horizontal and has a magnitude of 40 N. The figure given below is the block's speed v versus time t as the block moves along x - axis on the floor. What is the coefficient of kinetic friction between the block and the floor? [Take g=10 m/s2]
Answer» A $5 kg$ block is pushed along a floor by a constant applied force that is horizontal and has a magnitude of $40 N$ . The figure given below is the block's speed $v$ versus time $t$ as the block moves along $x$ - axis on the floor. What is the coefficient of kinetic friction between the block and the floor? [Take $g = 10 {m/s}^{2}$ ]

Discussion

16.	A rod of length 6 m has specific gravity ρ(=25/36). One end of the rod is tied to a 5 m long rope, which in turn is tied to the floor of a pool 10 m deep, as shown. Find the length (in m) of the part of rod which is out of water.
Answer» A rod of length $6 m$ has specific gravity $ρ (= 25 / 36)$ . One end of the rod is tied to a $5 m$ long rope, which in turn is tied to the floor of a pool $10 m$ deep, as shown. Find the length (in $m$ ) of the part of rod which is out of water.

Discussion

17.	In the circuit shown the capacitor of capacitance C is initially uncharged. Now the capacitor is connected in the circuit as shown. The charge passed through an imaginary circular loop parallel to the plates (also circular) and having the area equal to half of the area of the plates, in one time constant is :
Answer» In the circuit shown the capacitor of capacitance C is initially uncharged. Now the capacitor is connected in the circuit as shown. The charge passed through an imaginary circular loop parallel to the plates (also circular) and having the area equal to half of the area of the plates, in one time constant is :

17.

In the circuit shown the capacitor of capacitance C is initially uncharged. Now the capacitor is connected in the circuit as shown. The charge passed through an imaginary circular loop parallel to the plates (also circular) and having the area equal to half of the area of the plates, in one time constant is :

Answer»

In the circuit shown the capacitor of capacitance C is initially uncharged. Now the capacitor is connected in the circuit as shown. The charge passed through an imaginary circular loop parallel to the plates (also circular) and having the area equal to half of the area of the plates, in one time constant is :

Discussion

18.	The temperatures of two bodies A and B are 7270C and 1270 C. The ratio of rate of emission of radiations will be
Answer» The temperatures of two bodies A and B are $727^{0}$ C and $127^{0}$ C. The ratio of rate of emission of radiations will be

18.

The temperatures of two bodies A and B are 7270C and 1270 C. The ratio of rate of emission of radiations will be

Answer»

The temperatures of two bodies A and B are $727^{0}$ C and $127^{0}$ C. The ratio of rate of emission of radiations will be

Discussion

19.	Two spheres made of the same substance have diameters in the ratio 1:2. Their thermal capacities are in the ratio of
Answer» Two spheres made of the same substance have diameters in the ratio $1 : 2$ . Their thermal capacities are in the ratio of

Discussion

20.	A 30.0-cm-long wire having a mass of 10.0 g is fixed at the two ends and is vibrated in its fundamental mode. A 50.0-cm-long closed organ pipe, placed with its open end near the wire, is set up into resonance in its fundamental mode by the vibrating wire. Find the tension in the wire. Speed of sound in air = 340ms−1.
Answer» A 30.0-cm-long wire having a mass of 10.0 g is fixed at the two ends and is vibrated in its fundamental mode. A 50.0-cm-long closed organ pipe, placed with its open end near the wire, is set up into resonance in its fundamental mode by the vibrating wire. Find the tension in the wire. Speed of sound in air = $340 m s^{- 1}$ .

Discussion

21.	Consider a gravity-free hall in which an experimenter of mass 50 kg is resting on a t kg pillow, 8 ft above the floor of the hall. He pushes the pillow down so that it starts falling at a speed of 8 ft/s. The pillow makes a perfectly elastic collision with the floor, rebounds and reaches the experimenter's head. find the time elapsed in the process.
Answer» Consider a gravity-free hall in which an experimenter of mass 50 kg is resting on a t kg pillow, 8 ft above the floor of the hall. He pushes the pillow down so that it starts falling at a speed of 8 ft/s. The pillow makes a perfectly elastic collision with the floor, rebounds and reaches the experimenter's head. find the time elapsed in the process.

Discussion

22.	Distinguish between Responsibility, Authority and Accountability on the basis of : (i) Meaning (ii) Nature (iii) Flow of communication (iv) Actions
Answer» Distinguish between Responsibility, Authority and Accountability on the basis of : (i) Meaning (ii) Nature (iii) Flow of communication (iv) Actions

22.

Distinguish between Responsibility, Authority and Accountability on the basis of : (i) Meaning (ii) Nature (iii) Flow of communication (iv) Actions

Answer»

Distinguish between Responsibility, Authority and Accountability on the basis of :

(i) Meaning (ii) Nature

(iii) Flow of communication (iv) Actions

Discussion

23.	A particle starts from a point A and travels along the sold curve shown in figure. Find approximaterly the position B of the particle such that the average velocity between the position A and B has the same direction as the instantaneous velocity at B
Answer» A particle starts from a point A and travels along the sold curve shown in figure. Find approximaterly the position B of the particle such that the average velocity between the position A and B has the same direction as the instantaneous velocity at B

23.

A particle starts from a point A and travels along the sold curve shown in figure. Find approximaterly the position B of the particle such that the average velocity between the position A and B has the same direction as the instantaneous velocity at B

Answer»

A particle starts from a point A and travels along the sold curve shown in figure. Find approximaterly the position B of the particle such that the average velocity between the position A and B has the same direction as the instantaneous velocity at B

Discussion

24.	A ball of mass ′m′ moving horizontally which velocity ′u′ hits a wedge of mass ′M′. the wedge is situated on a smooth horizontal surface. If after striking wedge the ball starts moving in vertical direction and the wedge starts moving in horizontal plane. Calculate the coefficient of restitution e.
Answer» A ball of mass $^{'} m^{'}$ moving horizontally which velocity $^{'} u^{'}$ hits a wedge of mass $^{'} M^{'}$ . the wedge is situated on a smooth horizontal surface. If after striking wedge the ball starts moving in vertical direction and the wedge starts moving in horizontal plane. Calculate the coefficient of restitution $e$ .

24.

A ball of mass ′m′ moving horizontally which velocity ′u′ hits a wedge of mass ′M′. the wedge is situated on a smooth horizontal surface. If after striking wedge the ball starts moving in vertical direction and the wedge starts moving in horizontal plane. Calculate the coefficient of restitution e.

Answer»

A ball of mass $^{'} m^{'}$ moving horizontally which velocity $^{'} u^{'}$ hits a wedge of mass $^{'} M^{'}$ . the wedge is situated on a smooth horizontal surface. If after striking wedge the ball starts moving in vertical direction and the wedge starts moving in horizontal plane. Calculate the coefficient of restitution $e$ .

Discussion

25.	The capacity of a parallel plate condenser is . When a glass plate is placed between the plates of the conductor, its potential becomes 1/8thof the original value. The value of dielectric constant will be
Answer» The capacity of a parallel plate condenser is . When a glass plate is placed between the plates of the conductor, its potential becomes 1/8thof the original value. The value of dielectric constant will be

25.

The capacity of a parallel plate condenser is . When a glass plate is placed between the plates of the conductor, its potential becomes 1/8thof the original value. The value of dielectric constant will be

Answer»

The capacity of a parallel plate condenser is . When a glass plate is

placed between the plates of the conductor, its potential becomes 1/8thof

the original value. The value of dielectric constant will be

Discussion

26.	In figure the angle of inclination of the inclined plane is 30∘. Find the horizontal velocity V0 so that the particle hits the inclined plane perpendicularly.
Answer» In figure the angle of inclination of the inclined plane is $30^{\circ}$ . Find the horizontal velocity $V_{0}$ so that the particle hits the inclined plane perpendicularly.

Discussion

27.	A sample of ideal gas of some mass is taken through the cyclic process shown in the figure. The temperature of the gas at state A is TA = 200K, and at state C is TC = 1800K. Choose the correct option(s).
Answer» A sample of ideal gas of some mass is taken through the cyclic process shown in the figure. The temperature of the gas at state A is $T_{A}$ = 200K, and at state C is $T_{C}$ = 1800K. Choose the correct option(s).

Discussion

28.	A block A of mass M rests on a wedge B of mass 2M of inclination θ. There is sufficient friction between A and B so that A does not slip on B. If there is no friction between B and ground, the compression in spring is
Answer» A block $A$ of mass $M$ rests on a wedge $B$ of mass $2 M$ of inclination $θ$ . There is sufficient friction between $A$ and $B$ so that $A$ does not slip on $B$ . If there is no friction between $B$ and ground, the compression in spring is

Discussion

29.	Electric field close to plane of charge is shown in figure. External electric field in V/m is
Answer» Electric field close to plane of charge is shown in figure. External electric field in V/m is

Discussion

30.	A transverse wave is described by the equation y=y0sin 2π(ft−xλ). The maximum particle velocity is four times the wave velocity if
Answer» A transverse wave is described by the equation $y = y_{0} s i n 2 π (f t - \frac{x}{λ})$ . The maximum particle velocity is four times the wave velocity if

Discussion

31.	Consider a concave mirror and a convex lens (refractive index = 1.5) of focal length 10 cm each, separated by a distance of 50 cm in air as shown in the figure. An object is placed at a distance of 15 cm from the mirror. Its erect image formed by this combination has magnification M1.When the set up is kept in a medium of refractive index 76, the magnification becomes M2. The magnitude of ∣∣∣M2M1∣∣∣ is
Answer» Consider a concave mirror and a convex lens (refractive index = 1.5) of focal length $10 cm$ each, separated by a distance of $50 cm$ in air as shown in the figure. An object is placed at a distance of $15 cm$ from the mirror. Its erect image formed by this combination has magnification $M_{1}$ .When the set up is kept in a medium of refractive index $\frac{7}{6}$ , the magnification becomes $M_{2}$ . The magnitude of $∣ ∣ ∣ \frac{M_{2}}{M_{1}} ∣ ∣ ∣$ is

Discussion

32.	A particle of mass m is projected with velocity v at an angle θ with the horizontal. Find its angular momentum about the point of projection when it is at the highest point of its trajectory.
Answer» A particle of mass $m$ is projected with velocity $v$ at an angle $θ$ with the horizontal. Find its angular momentum about the point of projection when it is at the highest point of its trajectory.

Discussion

33.	A current carrying conductor is placed from West to East direction. What will be the direction of the force due to Earth's magnetic field?
Answer» A current carrying conductor is placed from West to East direction. What will be the direction of the force due to Earth's magnetic field?

Discussion

34.	A particle is projected with certain velocity at an angle α above the horizontal from the foot of an inclined plane having inclination of 30∘. If the particle strikes the plane normally then α is:
Answer» A particle is projected with certain velocity at an angle $α$ above the horizontal from the foot of an inclined plane having inclination of $30^{\circ}$ . If the particle strikes the plane normally then $α$ is:

Discussion

35.	A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?
Answer» A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces ${\to F}_{g r a v i t a t i o n a l}, {\to F}_{d r a g}$ and force on it caused by rotor i.e. ${\to F}_{r o t o r}$ . Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

35.

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

Answer»

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces ${\to F}_{g r a v i t a t i o n a l}, {\to F}_{d r a g}$ and force on it caused by rotor i.e. ${\to F}_{r o t o r}$ . Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

Discussion

36.	In the circuit shown, the battery is ideal and has voltage 21V. Reading of (A1) ammeter is 0.42A. When another identical ammeter is also connected across R reading of A1 becomes 0.5A, then resistance of ammeter in ohms is
Answer» In the circuit shown, the battery is ideal and has voltage 21V. Reading of $(A_{1})$ ammeter is 0.42A. When another identical ammeter is also connected across R reading of $A_{1}$ becomes 0.5A, then resistance of ammeter in ohms is

Discussion

37.	If, in Exercise 5.21, the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks: a) the stone moves radially outwards, b) the stone flies off tangentially from the instant the string breaks, c) the stone flies off at an angle with the tangent whose magnitude depends on the speed of the particle ?
Answer» If, in Exercise 5.21, the speed of the stone is increased beyond the maximum permissible value, and the string breaks suddenly, which of the following correctly describes the trajectory of the stone after the string breaks: a) the stone moves radially outwards, b) the stone flies off tangentially from the instant the string breaks, c) the stone flies off at an angle with the tangent whose magnitude depends on the speed of the particle ?

Discussion

38.	The ceiling of a hall is 40 m high. For maximum horizontal distance, the angle at which the ball may be thrown with a speed of 56 ms−1 without hitting the ceiling of the ball is (Take g=9.8 m/s2)
Answer» The ceiling of a hall is $40 m$ high. For maximum horizontal distance, the angle at which the ball may be thrown with a speed of $56 m s^{- 1}$ without hitting the ceiling of the ball is (Take $g = 9.8 m / s^{2}$ )

Discussion

39.	The moment of inertia of a solid sphere about an axis passing through the centre of gravity is 25MR2; then its radius of gyration about a parallel axis at a distance 2R from first axis is
Answer» The moment of inertia of a solid sphere about an axis passing through the centre of gravity is $\frac{2}{5} M R^{2}$ ; then its radius of gyration about a parallel axis at a distance $2 R$ from first axis is

Discussion

40.	One end of a cylindrical glass rod (μ=1.5) of radius 1.0 cm is rounded in the shape of a hemisphere. The rod is immersed in water (μ=43) and an object is placed in the water along the axis of the rod at a distance of 8.0 cm from the rounded edge. Locate the image of the object.
Answer» One end of a cylindrical glass rod $(μ = 1.5)$ of radius 1.0 cm is rounded in the shape of a hemisphere. The rod is immersed in water $(μ = \frac{4}{3})$ and an object is placed in the water along the axis of the rod at a distance of 8.0 cm from the rounded edge. Locate the image of the object.

Discussion

41.	A gas at absolute temperature 300 K has pressure p=4×1010 N/m2. Boltzmann constant k=1.38×10−23 J/K. The number of molecules per cm3 is of the order of
Answer» A gas at absolute temperature $300 K$ has pressure $p = 4 \times 10^{10} N / m^{2}$ . Boltzmann constant $k = 1.38 \times 10^{- 23} J / K$ . The number of molecules per $c m^{3}$ is of the order of

Discussion

42.	A juggler is juggling 7 balls simultaneously. If the time gap to pass ball from one hand to the other is 2 second then find the maximum height attained by each ball.
Answer» A juggler is juggling $7$ balls simultaneously. If the time gap to pass ball from one hand to the other is $2$ second then find the maximum height attained by each ball.

Discussion

43.	A sphere of radius R and density ρ1 is dropped in a liquid of density σ. Its terminal velocity is v1 . If another sphere of radius R and density ρ2 is dropped in the same liquid, its terminal velocity will be:
Answer» A sphere of radius $R$ and density $ρ_{1}$ is dropped in a liquid of density $σ$ . Its terminal velocity is $v_{1}$ . If another sphere of radius $R$ and density $ρ_{2}$ is dropped in the same liquid, its terminal velocity will be:

Discussion

44.	A rod AB rests with the end A on rough horizontal ground such that end A is prevented from sliding to the right. And the end B against a smooth vertical wall. The rod is uniform and of weight W. If the rod is in a stationary position as shown in figure, the number of forces acting in the FBD of rod is/are?
Answer» A rod $A B$ rests with the end $A$ on rough horizontal ground such that end A is prevented from sliding to the right. And the end B against a smooth vertical wall. The rod is uniform and of weight $W$ . If the rod is in a stationary position as shown in figure, the number of forces acting in the FBD of rod is/are?

Discussion

45.	State how does lateral displacement through a glass slab depend upon: 1. Thickness of the glass slab 2. Angle of incidence
Answer» State how does lateral displacement through a glass slab depend upon: 1. Thickness of the glass slab 2. Angle of incidence

Discussion

46.	Two blocks of masses m1=m2=m are connected by a string of negligible mass which passes over a frictionless pulley fixed on the top of an inclined plane as shown in the figure. When the angle of inclination θ=30∘, the mass m1 just begins to move up the inclined plane. What is the coefficient of friction between blockm1 and the inclined plane?
Answer» Two blocks of masses $m_{1} = m_{2} = m$ are connected by a string of negligible mass which passes over a frictionless pulley fixed on the top of an inclined plane as shown in the figure. When the angle of inclination $θ = 30^{\circ}$ , the mass $m_{1}$ just begins to move up the inclined plane. What is the coefficient of friction between block $m_{1}$ and the inclined plane?

Discussion

47.	Find the maximum force F to be applied for the system shown, so that the two blocks move together. Take g=10 m/s2.
Answer» Find the maximum force $F$ to be applied for the system shown, so that the two blocks move together. Take $g = 10 {m/s}^{2}$ .

Discussion

48.	Sodium has a work function of 2.28 eV. Let's say, I introduce a very strong external electric field, which is applying a force on the electrons outwards, thus giving them electrical potential energy of 1.5 eV each. What is the work function of the metal surface in such a case?
Answer» Sodium has a work function of 2.28 eV. Let's say, I introduce a very strong external electric field, which is applying a force on the electrons outwards, thus giving them electrical potential energy of 1.5 eV each. What is the work function of the metal surface in such a case?

Discussion

49.	Suppose, one wishes to construct a 1.0 farad capacitor using circular discs. If the separation between the discs be kept at 1.0 mm, what would be the radius of the discs ?
Answer» Suppose, one wishes to construct a 1.0 farad capacitor using circular discs. If the separation between the discs be kept at 1.0 mm, what would be the radius of the discs ?

Discussion

50.	The ends of two rods of different materials, having thermal conductivities, radii of cross-section and lengths in the ratio 1 : 2, are maintained at the same temperature difference. If the rate of flow of heat in the larger rod is 4 cal s−1, then that in shorter rod is( in cal s−1) will be
Answer» The ends of two rods of different materials, having thermal conductivities, radii of cross-section and lengths in the ratio 1 : 2, are maintained at the same temperature difference. If the rate of flow of heat in the larger rod is ${4 cal s}^{- 1}$ , then that in shorter rod is( in ${cal s}^{- 1}$ ) will be

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

What does generally the load resistance signify in half wave rectifier circuit diagram?

A block A kept on an inclined surface just begins to slide if the inclination is 30∘. The block is replaced by another block B and it is found that it just begins to slide if the inclination is 40∘.

The figure shows a circular wire - loop of radius a, carrying a current i, placed in a perpendicular magnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. (b) Find the force of compression in the wire.

A block of mass m initially at rest is dropped from a height h on to a spring of force constant k. the maximum compression in the spring is x then

A hollow spherical body of inner and outer radii 6 cm and 8 cm respectively floats half-submerged in water. Find the density of the material of the sphere.

A constant torque of 31.4 Nm is exerted on a pivoted wheel. If angular acceleration of wheel is 4π rads−2, then the moment of inertia of wheel is nearly equal to

A particle of mass m is released from point A on smooth fixed circular track as shown. If the particle is released from rest at t = 0, then variation of normal reaction N with (θ) angular displacement from initial position is

In the circuit, initially switch S has been open for a long time. It is then closed for a long time. The charge on the capacitor (in μC) changes by an amount of Here, C=30 μF,E1=1 V,E2=3 V,R1=0.2 Ω,R2=0.4 Ω.

A rod of length 6 m has specific gravity ρ(=25/36). One end of the rod is tied to a 5 m long rope, which in turn is tied to the floor of a pool 10 m deep, as shown. Find the length (in m) of the part of rod which is out of water.

The temperatures of two bodies A and B are 7270C and 1270 C. The ratio of rate of emission of radiations will be

Two spheres made of the same substance have diameters in the ratio 1:2. Their thermal capacities are in the ratio of

Distinguish between Responsibility, Authority and Accountability on the basis of : (i) Meaning (ii) Nature (iii) Flow of communication (iv) Actions

A particle starts from a point A and travels along the sold curve shown in figure. Find approximaterly the position B of the particle such that the average velocity between the position A and B has the same direction as the instantaneous velocity at B

The capacity of a parallel plate condenser is . When a glass plate is placed between the plates of the conductor, its potential becomes 1/8thof the original value. The value of dielectric constant will be

In figure the angle of inclination of the inclined plane is 30∘. Find the horizontal velocity V0 so that the particle hits the inclined plane perpendicularly.

A sample of ideal gas of some mass is taken through the cyclic process shown in the figure. The temperature of the gas at state A is TA = 200K, and at state C is TC = 1800K. Choose the correct option(s).

A block A of mass M rests on a wedge B of mass 2M of inclination θ. There is sufficient friction between A and B so that A does not slip on B. If there is no friction between B and ground, the compression in spring is

Electric field close to plane of charge is shown in figure. External electric field in V/m is

A transverse wave is described by the equation y=y0sin 2π(ft−xλ). The maximum particle velocity is four times the wave velocity if

A particle of mass m is projected with velocity v at an angle θ with the horizontal. Find its angular momentum about the point of projection when it is at the highest point of its trajectory.

A current carrying conductor is placed from West to East direction. What will be the direction of the force due to Earth's magnetic field?

A particle is projected with certain velocity at an angle α above the horizontal from the foot of an inclined plane having inclination of 30∘. If the particle strikes the plane normally then α is:

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

In the circuit shown, the battery is ideal and has voltage 21V. Reading of (A1) ammeter is 0.42A. When another identical ammeter is also connected across R reading of A1 becomes 0.5A, then resistance of ammeter in ohms is

The ceiling of a hall is 40 m high. For maximum horizontal distance, the angle at which the ball may be thrown with a speed of 56 ms−1 without hitting the ceiling of the ball is (Take g=9.8 m/s2)

The moment of inertia of a solid sphere about an axis passing through the centre of gravity is 25MR2; then its radius of gyration about a parallel axis at a distance 2R from first axis is

One end of a cylindrical glass rod (μ=1.5) of radius 1.0 cm is rounded in the shape of a hemisphere. The rod is immersed in water (μ=43) and an object is placed in the water along the axis of the rod at a distance of 8.0 cm from the rounded edge. Locate the image of the object.

A gas at absolute temperature 300 K has pressure p=4×1010 N/m2. Boltzmann constant k=1.38×10−23 J/K. The number of molecules per cm3 is of the order of

A juggler is juggling 7 balls simultaneously. If the time gap to pass ball from one hand to the other is 2 second then find the maximum height attained by each ball.

A sphere of radius R and density ρ1 is dropped in a liquid of density σ. Its terminal velocity is v1 . If another sphere of radius R and density ρ2 is dropped in the same liquid, its terminal velocity will be:

State how does lateral displacement through a glass slab depend upon: 1. Thickness of the glass slab 2. Angle of incidence

Find the maximum force F to be applied for the system shown, so that the two blocks move together. Take g=10 m/s2.

Sodium has a work function of 2.28 eV. Let's say, I introduce a very strong external electric field, which is applying a force on the electrons outwards, thus giving them electrical potential energy of 1.5 eV each. What is the work function of the metal surface in such a case?

Suppose, one wishes to construct a 1.0 farad capacitor using circular discs. If the separation between the discs be kept at 1.0 mm, what would be the radius of the discs ?

The ends of two rods of different materials, having thermal conductivities, radii of cross-section and lengths in the ratio 1 : 2, are maintained at the same temperature difference. If the rate of flow of heat in the larger rod is 4 cal s−1, then that in shorter rod is( in cal s−1) will be