50278 + Interview Questions in Physics

1.	A refrigerator whose coefficient of performance is 5, extracts heat from the cooling compartment at the rate of 250 J/cycle. Find the amount of heat discharged per cycle to the room.
Answer» A refrigerator whose coefficient of performance is $5$ , extracts heat from the cooling compartment at the rate of $250 J/cycle$ . Find the amount of heat discharged per cycle to the room.

Discussion

2.	A muonic atom contains a nucleus of charge Ze and a negative muon, μ−, moving about it. The μ− is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass. What is the wavelength of the first line(in ∘A) in the Lyman series for such an atom?
Answer» A muonic atom contains a nucleus of charge Ze and a negative muon, $μ^{-}$ , moving about it. The $μ^{-}$ is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass. What is the wavelength of the first line( $in \circ A$ ) in the Lyman series for such an atom?

Discussion

3.	A charged water droplet hangs from ceiling of a room which has a uniform vertically upwards electrical field of strength 4.00 × 105 NC−1 . This field levitates and preventsa droplet of mass 1.0 ×10−4kg from falling. Can you find the net charge on the droplet?
Answer» A charged water droplet hangs from ceiling of a room which has a uniform vertically upwards electrical field of strength 4.00 $\times 10^{5} N C^{- 1}$ . This field levitates and preventsa droplet of mass 1.0 $\times 10^{- 4}$ kg from falling. Can you find the net charge on the droplet?

Discussion

4.	Find the average velocity of a projectile between the instants it crosses one third of the maximum height. It is projected with u making an angle θ with the vertical.
Answer» Find the average velocity of a projectile between the instants it crosses one third of the maximum height. It is projected with $u$ making an angle $θ$ with the vertical.

Discussion

5.	A steel ire 0.72 m long has a mass of 5x10^-3 kg. If the wire is under a tension of 60N then what is the speed of transverse waves on the wire?
Answer» A steel ire 0.72 m long has a mass of 5x10^-3 kg. If the wire is under a tension of 60N then what is the speed of transverse waves on the wire?

Discussion

6.	Two wires A and B are made of same material. The wire A has a length l and diameter r while the wire B has length 2l and diameter 2r. If the two wires are stretched by the same force, the elongation in A divided by elongation in B is
Answer» Two wires A and B are made of same material. The wire A has a length l and diameter r while the wire B has length 2l and diameter 2r. If the two wires are stretched by the same force, the elongation in A divided by elongation in B is

Discussion

7.	A steel wire of length 20cm is stretched to increase the length by 0.2cm find the lateral strain in the wire if Poisson's ratio is 0.19
Answer» A steel wire of length 20cm is stretched to increase the length by 0.2cm find the lateral strain in the wire if Poisson's ratio is 0.19

Discussion

8.	A particle moves along a straight line and its velocity depends on time as v=6t−3t2 where v is in m/s and t in seconds. Find the average speed for first 4 seconds. (in m/s)
Answer» A particle moves along a straight line and its velocity depends on time as $v = 6 t - 3 t^{2}$ where $v$ is in $m/s$ and $t$ in seconds. Find the average speed for first 4 seconds. (in $m/s$ )

Discussion

9.	A body covers 200cm in the first 2sec and 220cm in next 4sec under constant acceleration then velocity of body after 7sec is?
Answer» A body covers 200cm in the first 2sec and 220cm in next 4sec under constant acceleration then velocity of body after 7sec is?

Discussion

10.	Why coolant constant K depends on the medium? If most of the space inside an atom is is actually vacuum and all the electrostatic attraction and repulsion that happens from one medium to another medium like electrons flow have to happen from from one atom to another atom and most of the space inside the atom itself is empty or vacuum so what my answer to this question would be so if most of the space inside an atom is empty then culomb constant or permitivity should depend on intermolecular spaces then medium and instead of dielectric constant or absolute permittivity it should only be permittivity of vacuum
Answer» Why coolant constant K depends on the medium? If most of the space inside an atom is is actually vacuum and all the electrostatic attraction and repulsion that happens from one medium to another medium like electrons flow have to happen from from one atom to another atom and most of the space inside the atom itself is empty or vacuum so what my answer to this question would be so if most of the space inside an atom is empty then culomb constant or permitivity should depend on intermolecular spaces then medium and instead of dielectric constant or absolute permittivity it should only be permittivity of vacuum

Discussion

11.	Two S.H.M's of unequal amplitude with same frequency (act) on a particle at right angle, with a phase difference of π2. The resultant motion is:
Answer» Two S.H.M's of unequal amplitude with same frequency (act) on a particle at right angle, with a phase difference of $\frac{π}{2}$ . The resultant motion is:

Discussion

12.	In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.
Answer» In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is $μ_{s}$ .

12.

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.

Answer»

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is $μ_{s}$ .

Discussion

13.	In a hydraulic lift, compressed air exerts a force F1 on a small piston having a radius of 5 cm. This pressure is transmitted to a second piston of radius 15 cm. If the mass of the load to be lifted is 1350 kg, calculate the pressure acting on the smaller piston. [Take g=10 m/s2]
Answer» In a hydraulic lift, compressed air exerts a force $F_{1}$ on a small piston having a radius of $5 cm$ . This pressure is transmitted to a second piston of radius $15 cm$ . If the mass of the load to be lifted is $1350 kg$ , calculate the pressure acting on the smaller piston. [Take $g = 10 {m/s}^{2}$ ]

Discussion

14.	A wind turbine is rotating with an angular velocity of 180 rev/min. It comes to rest after 5 mins. Total number of revolutions made by it before it stops (Assume angular retardation is uniform)
Answer» A wind turbine is rotating with an angular velocity of $180 rev/min$ . It comes to rest after $5 mins$ . Total number of revolutions made by it before it stops (Assume angular retardation is uniform)

Discussion

15.	A person of mass 60 kg is in a lift. The change in the apparent weight of the person, when the lift accelerates up with an acceleration of 2 m/s2 and then down with an acceleration of 2 m/s2 is
Answer» A person of mass $60 kg$ is in a lift. The change in the apparent weight of the person, when the lift accelerates up with an acceleration of $2 {m/s}^{2}$ and then down with an acceleration of $2 {m/s}^{2}$ is

Discussion

16.	A spring 40 mm long is stretched by applying a force. If 10 N force is required to stretch the spring through 1 mm, then work done in stretching the spring through 40 mm is
Answer» A spring $40 mm$ long is stretched by applying a force. If $10 N$ force is required to stretch the spring through $1 mm$ , then work done in stretching the spring through $40 mm$ is

Discussion

17.	In a metre bridge experiment, two unknown resistances X and Y are connected to left and right gaps respectively and the balancing point is obtained at 20 cm from right. What will be the new position of the null point from left if one decides to balance a resistance of 4X against Y? (Assume that length of wire of metre bridge is 120 cm.)
Answer» In a metre bridge experiment, two unknown resistances X and Y are connected to left and right gaps respectively and the balancing point is obtained at 20 cm from right. What will be the new position of the null point from left if one decides to balance a resistance of 4X against Y? (Assume that length of wire of metre bridge is 120 cm.)

Discussion

18.	Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces to be acting : A) If charges have different magnitude and signs , the system will be in equilibrium. B) system will be in equilibrium if charges have same magnitude but different signs. C) the system can never be in equilibrium. D) the system will be in equilibrium if charges rotate about the centre. Please explain the above question in detail
Answer» Three point charges are placed at the corners of an equilateral triangle. Assuming only electrostatic forces to be acting : A) If charges have different magnitude and signs , the system will be in equilibrium. B) system will be in equilibrium if charges have same magnitude but different signs. C) the system can never be in equilibrium. D) the system will be in equilibrium if charges rotate about the centre. Please explain the above question in detail

Discussion

19.	The time dependence of the position of a particle of mass 2 kg is given by →r(t)=2t^i−3t2^j m. Its angular momentum with respect to origin at time t=2 s is given by −N^k kg.m2/s, the value of N is
Answer» The time dependence of the position of a particle of mass $2 k g$ is given by $\to r (t) = 2 t^i - 3 t^{2}^j m$ . Its angular momentum with respect to origin at time $t = 2 s$ is given by $- N^k {kg.m}^{2} /s$ , the value of $N$ is

Discussion

20.	Explain the statement: The work done by the tension in the string of a simple pendulum during one complete oscillation is equal to zero.
Answer» Explain the statement: The work done by the tension in the string of a simple pendulum during one complete oscillation is equal to zero.

Discussion

21.	An rms voltage of 110 V is applied across a RLC series circuit having a resistance 11W and an impedance 22W. The power consumed is
Answer» An rms voltage of 110 V is applied across a RLC series circuit having a resistance 11W and an impedance 22W. The power consumed is

Discussion

22.	Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is
Answer» Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is

Discussion

23.	A block B moves with a velocity u relative to the wedge A. If the velocity of the wedge is v as shown in figure, what should be the value of θ so that the block B moves vertically as seen from the ground?
Answer» A block B moves with a velocity $u$ relative to the wedge $A$ . If the velocity of the wedge is $v$ as shown in figure, what should be the value of $θ$ so that the block $B$ moves vertically as seen from the ground?

Discussion

24.	A small air bubble is at the inner surface of the bottom of a beaker filled with cold water. Now water of the beaker is heated. The size of bubble increases. The reason for this may be
Answer» A small air bubble is at the inner surface of the bottom of a beaker filled with cold water. Now water of the beaker is heated. The size of bubble increases. The reason for this may be

Discussion

25.	As shown in figure, at the mouth of the tap the area of cross-section is 2.5 cm2 and the speed of water is 3 m/s. The area of cross-section of the water column 80 cm below the tap is
Answer» As shown in figure, at the mouth of the tap the area of cross-section is 2.5 $c m^{2}$ and the speed of water is 3 m/s. The area of cross-section of the water column 80 cm below the tap is

25.

As shown in figure, at the mouth of the tap the area of cross-section is 2.5 cm2 and the speed of water is 3 m/s. The area of cross-section of the water column 80 cm below the tap is

Answer»

As shown in figure, at the mouth of the tap the area of cross-section is 2.5 $c m^{2}$ and the speed of water is 3 m/s. The area of cross-section of the water column 80 cm below the tap is

Discussion

26.	The amplitude of a particle executing S.H.M. with frequency of 60 Hz is 0.01 m. The maximum value of the acceleration of the particle is
Answer» The amplitude of a particle executing S.H.M. with frequency of 60 Hz is 0.01 m. The maximum value of the acceleration of the particle is

Discussion

27.	What question can be asked in order to get the given phrase as the answer? The ones on the shelf
Answer» What question can be asked in order to get the given phrase as the answer? The ones on the shelf

27.

What question can be asked in order to get the given phrase as the answer? The ones on the shelf

Answer»

What question can be asked in order to get the given phrase as the answer?

The ones on the shelf

Discussion

28.	The coefficients of static and kinetic friction between a body and the surface are 0.75 and 0.5 respectively. A force is applied to the body to make it just slide with a constant acceleration which is equal to
Answer» The coefficients of static and kinetic friction between a body and the surface are 0.75 and 0.5 respectively. A force is applied to the body to make it just slide with a constant acceleration which is equal to

Discussion

29.	A wire PQRS shown in Fig. carries a current l. The radius of the circular part of the wire r. The magnetic field at the centre O of the circular part of the wire is given by
Answer» A wire PQRS shown in Fig. carries a current l. The radius of the circular part of the wire r. The magnetic field at the centre O of the circular part of the wire is given by

Discussion

30.	The relation between internal energy U, pressure P and volume V of a gas in an adiabatic process is: U = a + bPV where a = b = 3. The ratio of specific heats is (Answer up to two decimal places)
Answer» The relation between internal energy U, pressure P and volume V of a gas in an adiabatic process is: U = a + bPV where a = b = 3. The ratio of specific heats is (Answer up to two decimal places)

Discussion

31.	For a particle executing simple harmonic motion, the kinetic energy K is given by K = K0 cos2 ω t . The maximum value of potential energy is
Answer» For a particle executing simple harmonic motion, the kinetic energy K is given by K = $K_{0} c o s^{2} ω t$ . The maximum value of potential energy is

Discussion

32.	When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon
Answer» When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon

Discussion

33.	The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.
Answer» The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.

Discussion

34.	Magnetic field intensity is defined as
Answer» Magnetic field intensity is defined as

Discussion

35.	The work done in placing a charge of 8×10−18 coulomb on a condenser of capacity 100 micro-Farad is: [AIEEE-2003]
Answer» The work done in placing a charge of $8 \times 10^{- 18}$ coulomb on a condenser of capacity 100 micro-Farad is: [AIEEE-2003]

Discussion

36.	(a) A ray 'PQ' of light is incident on the face AB of a glass prism ABC (as shown in the figure) and emerges out of the face AC. Trace the path of the ray. Show that ∠i+∠e=∠A+∠δ. When δ and e denote the angle of deviation and angle of emergence respectively. Plot a graph showing the variation of the angle of deviation as a function of angle of incidence. State the condition under which δ is minimum. (b) Find out the relation between the refractive index (μ) of the glass prism and ∠A for the case when the angle of prism (A) is equal to the angle of minimum deviation (δm). Hence obtain the value of the refractive index for angle of prism A=60∘.
Answer» (a) A ray 'PQ' of light is incident on the face AB of a glass prism ABC (as shown in the figure) and emerges out of the face AC. Trace the path of the ray. Show that $∠ i + ∠ e = ∠ A + ∠ δ$ . When $δ$ and e denote the angle of deviation and angle of emergence respectively. Plot a graph showing the variation of the angle of deviation as a function of angle of incidence. State the condition under which $δ$ is minimum. (b) Find out the relation between the refractive index ( $μ$ ) of the glass prism and $∠ A$ for the case when the angle of prism (A) is equal to the angle of minimum deviation $(δ_{m})$ . Hence obtain the value of the refractive index for angle of prism $A = 60^{\circ}$ .

Discussion

37.	Anything we can answer with lots of scientific evidence, we call it as _________
Answer» Anything we can answer with lots of scientific evidence, we call it as _________

Discussion

38.	An electrically heating coil was placed in a calorimeter containing 360 gm of water at 10∘C. The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes. (J = 4.2 Joule/cal.)
Answer» An electrically heating coil was placed in a calorimeter containing 360 gm of water at $10^{\circ} C$ . The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes. (J = 4.2 Joule/cal.)

Discussion

39.	Consider the situation shown in figure. The wire P Q has mass m, resistance r and can slide on the smooth, horizontal parallel rails separted by a dist ance l. The resistance of the rails is negligible. A uniform magnetic field B exicts in the rectangular region and a resistance R connects the rails outsi de the field region. At t = 0, the wire PQ is pushed towards right with a speed vv. Find (a) The current in the loop at an instant when the speed of the wire PQ is v, (b) The acceleration of the wire at this instant (c) The velocity v as a function of x and (d) The maximum distance the wire will move.
Answer» Consider the situation shown in figure. The wire P Q has mass m, resistance r and can slide on the smooth, horizontal parallel rails separted by a dist ance l. The resistance of the rails is negligible. A uniform magnetic field B exicts in the rectangular region and a resistance R connects the rails outsi de the field region. At t = 0, the wire PQ is pushed towards right with a speed $v_{v}$ . Find (a) The current in the loop at an instant when the speed of the wire PQ is v, (b) The acceleration of the wire at this instant (c) The velocity v as a function of x and (d) The maximum distance the wire will move.

39.

Consider the situation shown in figure. The wire P Q has mass m, resistance r and can slide on the smooth, horizontal parallel rails separted by a dist ance l. The resistance of the rails is negligible. A uniform magnetic field B exicts in the rectangular region and a resistance R connects the rails outsi de the field region. At t = 0, the wire PQ is pushed towards right with a speed vv. Find (a) The current in the loop at an instant when the speed of the wire PQ is v, (b) The acceleration of the wire at this instant (c) The velocity v as a function of x and (d) The maximum distance the wire will move.

Answer»

Consider the situation shown in figure. The wire P Q has mass m, resistance r and can slide on the smooth, horizontal parallel rails separted by a dist ance l. The resistance of the rails is negligible. A uniform magnetic field B exicts in the rectangular region and a resistance R connects the rails outsi de the field region. At t = 0, the wire PQ is pushed towards right with a speed $v_{v}$ . Find

(a) The current in the loop at an instant when the speed of the wire PQ is v,

(b) The acceleration of the wire at this instant

(c) The velocity v as a function of x and

(d) The maximum distance the wire will move.

Discussion

40.	A ball of mass 4 kg moving with a velocity of 12 m/s impinges directly on another ball of mass 8 kg moving with velocity of 4 m/s in the same direction. Find their velocities after impact (if e = 0.5)
Answer» A ball of mass 4 kg moving with a velocity of 12 m/s impinges directly on another ball of mass 8 kg moving with velocity of 4 m/s in the same direction. Find their velocities after impact (if $e$ = 0.5)

Discussion

41.	If a spring extends by x on loading, then the energy stored by the spring is (if T is tension in the spring and k is spring constant)
Answer» If a spring extends by x on loading, then the energy stored by the spring is (if T is tension in the spring and k is spring constant)

Discussion

42.	An infinite line charge produces a field of 18* 10^4 N/C at a distance of 2 metre from it. The linear charge density is? 1) 10^-5 2) 2* 10^-5 3) zero 4) 4* 10^-5
Answer» An infinite line charge produces a field of 18* 10^4 N/C at a distance of 2 metre from it. The linear charge density is? 1) 10^-5 2) 2* 10^-5 3) zero 4) 4* 10^-5

Discussion

43.	A rectangular block of mass m and area of cross-section A floats in a liquid of density ρ. If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period T. Then,
Answer» A rectangular block of mass $m$ and area of cross-section $A$ floats in a liquid of density $ρ$ . If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period $T$ . Then,

Discussion

44.	Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index μ is placed on face AC of the pr 9 is m. The prism is made of glass of refractive index 32. The limits of μ for which total internal reflection takes place on face AC is
Answer» Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index $μ$ is placed on face AC of the pr 9 is m. The prism is made of glass of refractive index $\frac{3}{2}$ . The limits of $μ$ for which total internal reflection takes place on face AC is

Discussion

45.	A charged ball B hangs from a silk thread S, which makes an angle θ with a large charged conducting sheet P, as shown in the figure. The surface charge density σ of the sheet is proportional to
Answer» A charged ball B hangs from a silk thread S, which makes an angle $θ$ with a large charged conducting sheet P, as shown in the figure. The surface charge density $σ$ of the sheet is proportional to

45.

A charged ball B hangs from a silk thread S, which makes an angle θ with a large charged conducting sheet P, as shown in the figure. The surface charge density σ of the sheet is proportional to

Answer»

A charged ball B hangs from a silk thread S, which makes an angle $θ$ with a large charged conducting sheet P, as shown in the figure. The surface charge density $σ$ of the sheet is proportional to

Discussion

46.	A magnetic dipole of magnetic moment 1.44 A m2 is placed horizontally with the north pole pointing towards north. Find the position of the neutral point if the horizontal component of the earth's magnetic field is 18μT.
Answer» A magnetic dipole of magnetic moment 1.44 A $m^{2}$ is placed horizontally with the north pole pointing towards north. Find the position of the neutral point if the horizontal component of the earth's magnetic field is $18 μ T$ .

Discussion

47.	The mass m attached to a spring oscillates with a period of 2s. If mass is increased by 2 kg, the period increase by 1s. Find the initial mass M assuming that Hooke’s law is obeyed
Answer» The mass m attached to a spring oscillates with a period of 2s. If mass is increased by 2 kg, the period increase by 1s. Find the initial mass M assuming that Hooke’s law is obeyed

Discussion

48.	Consider the spring-mass system, with the mass submerged in water as shown in the figure. If mass is released with spring at natural length, then momentum-position diagram for one cycle of this system is (take down direction negative) (given density of mass is more than density of water).
Answer» Consider the spring-mass system, with the mass submerged in water as shown in the figure. If mass is released with spring at natural length, then momentum-position diagram for one cycle of this system is (take down direction negative) (given density of mass is more than density of water).

Discussion

49.	Two identical balls each of radii r are kept on a horizontal plane with their centers d distance apart. A third identical ball collides elastically with both the balls symmetrically as shown in the figure. If the third ball comes to rest after the collision, d should be
Answer» Two identical balls each of radii $r$ are kept on a horizontal plane with their centers $d$ distance apart. A third identical ball collides elastically with both the balls symmetrically as shown in the figure. If the third ball comes to rest after the collision, $d$ should be

Discussion

50.	Sixty percent of given sample of oxygen gas when raised to a high temperature dissociates into atoms. Ratio of its initial heat capacity (at constant volume) to its final heat capacity (at constant volume) will be
Answer» Sixty percent of given sample of oxygen gas when raised to a high temperature dissociates into atoms. Ratio of its initial heat capacity (at constant volume) to its final heat capacity (at constant volume) will be

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A refrigerator whose coefficient of performance is 5, extracts heat from the cooling compartment at the rate of 250 J/cycle. Find the amount of heat discharged per cycle to the room.

A muonic atom contains a nucleus of charge Ze and a negative muon, μ−, moving about it. The μ− is an elementary charge with -e and a mass that is approximately 200 times as large as an electron mass. What is the wavelength of the first line(in ∘A) in the Lyman series for such an atom?

A charged water droplet hangs from ceiling of a room which has a uniform vertically upwards electrical field of strength 4.00 × 105 NC−1 . This field levitates and preventsa droplet of mass 1.0 ×10−4kg from falling. Can you find the net charge on the droplet?

Find the average velocity of a projectile between the instants it crosses one third of the maximum height. It is projected with u making an angle θ with the vertical.

A steel ire 0.72 m long has a mass of 5x10^-3 kg. If the wire is under a tension of 60N then what is the speed of transverse waves on the wire?

Two wires A and B are made of same material. The wire A has a length l and diameter r while the wire B has length 2l and diameter 2r. If the two wires are stretched by the same force, the elongation in A divided by elongation in B is

A steel wire of length 20cm is stretched to increase the length by 0.2cm find the lateral strain in the wire if Poisson's ratio is 0.19

A particle moves along a straight line and its velocity depends on time as v=6t−3t2 where v is in m/s and t in seconds. Find the average speed for first 4 seconds. (in m/s)

A body covers 200cm in the first 2sec and 220cm in next 4sec under constant acceleration then velocity of body after 7sec is?

Two S.H.M's of unequal amplitude with same frequency (act) on a particle at right angle, with a phase difference of π2. The resultant motion is:

In the following figure force F is gradually increased from zero. Draw the graph between applied force F and tension T in the string. The coefficient of static friction between the block and the ground is μs.

In a hydraulic lift, compressed air exerts a force F1 on a small piston having a radius of 5 cm. This pressure is transmitted to a second piston of radius 15 cm. If the mass of the load to be lifted is 1350 kg, calculate the pressure acting on the smaller piston. [Take g=10 m/s2]

A wind turbine is rotating with an angular velocity of 180 rev/min. It comes to rest after 5 mins. Total number of revolutions made by it before it stops (Assume angular retardation is uniform)

A person of mass 60 kg is in a lift. The change in the apparent weight of the person, when the lift accelerates up with an acceleration of 2 m/s2 and then down with an acceleration of 2 m/s2 is

A spring 40 mm long is stretched by applying a force. If 10 N force is required to stretch the spring through 1 mm, then work done in stretching the spring through 40 mm is

The time dependence of the position of a particle of mass 2 kg is given by →r(t)=2t^i−3t2^j m. Its angular momentum with respect to origin at time t=2 s is given by −N^k kg.m2/s, the value of N is

Explain the statement: The work done by the tension in the string of a simple pendulum during one complete oscillation is equal to zero.

An rms voltage of 110 V is applied across a RLC series circuit having a resistance 11W and an impedance 22W. The power consumed is

Kinetic energy with which the electrons are emitted from the metal surface due to photoelectric effect is

A block B moves with a velocity u relative to the wedge A. If the velocity of the wedge is v as shown in figure, what should be the value of θ so that the block B moves vertically as seen from the ground?

A small air bubble is at the inner surface of the bottom of a beaker filled with cold water. Now water of the beaker is heated. The size of bubble increases. The reason for this may be

As shown in figure, at the mouth of the tap the area of cross-section is 2.5 cm2 and the speed of water is 3 m/s. The area of cross-section of the water column 80 cm below the tap is

The amplitude of a particle executing S.H.M. with frequency of 60 Hz is 0.01 m. The maximum value of the acceleration of the particle is

What question can be asked in order to get the given phrase as the answer? The ones on the shelf

The coefficients of static and kinetic friction between a body and the surface are 0.75 and 0.5 respectively. A force is applied to the body to make it just slide with a constant acceleration which is equal to

A wire PQRS shown in Fig. carries a current l. The radius of the circular part of the wire r. The magnetic field at the centre O of the circular part of the wire is given by

The relation between internal energy U, pressure P and volume V of a gas in an adiabatic process is: U = a + bPV where a = b = 3. The ratio of specific heats is (Answer up to two decimal places)

For a particle executing simple harmonic motion, the kinetic energy K is given by K = K0 cos2 ω t . The maximum value of potential energy is

When light falls on a metal surface, the maximum kinetic energy of the emitted photo-electrons depends upon

The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.

Magnetic field intensity is defined as

The work done in placing a charge of 8×10−18 coulomb on a condenser of capacity 100 micro-Farad is: [AIEEE-2003]

Anything we can answer with lots of scientific evidence, we call it as _________

An electrically heating coil was placed in a calorimeter containing 360 gm of water at 10∘C. The coil consumes energy at the rate of 90 watt. The water equivalent of the calorimeter and the coil is 40 gm. Calculate, what will be the temperature of the water after 10 minutes. (J = 4.2 Joule/cal.)

A ball of mass 4 kg moving with a velocity of 12 m/s impinges directly on another ball of mass 8 kg moving with velocity of 4 m/s in the same direction. Find their velocities after impact (if e = 0.5)

If a spring extends by x on loading, then the energy stored by the spring is (if T is tension in the spring and k is spring constant)

An infinite line charge produces a field of 18* 10^4 N/C at a distance of 2 metre from it. The linear charge density is? 1) 10^-5 2) 2* 10^-5 3) zero 4) 4* 10^-5

A rectangular block of mass m and area of cross-section A floats in a liquid of density ρ. If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period T. Then,

Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index μ is placed on face AC of the pr 9 is m. The prism is made of glass of refractive index 32. The limits of μ for which total internal reflection takes place on face AC is

A charged ball B hangs from a silk thread S, which makes an angle θ with a large charged conducting sheet P, as shown in the figure. The surface charge density σ of the sheet is proportional to

A magnetic dipole of magnetic moment 1.44 A m2 is placed horizontally with the north pole pointing towards north. Find the position of the neutral point if the horizontal component of the earth's magnetic field is 18μT.

The mass m attached to a spring oscillates with a period of 2s. If mass is increased by 2 kg, the period increase by 1s. Find the initial mass M assuming that Hooke’s law is obeyed

Consider the spring-mass system, with the mass submerged in water as shown in the figure. If mass is released with spring at natural length, then momentum-position diagram for one cycle of this system is (take down direction negative) (given density of mass is more than density of water).

Two identical balls each of radii r are kept on a horizontal plane with their centers d distance apart. A third identical ball collides elastically with both the balls symmetrically as shown in the figure. If the third ball comes to rest after the collision, d should be

Sixty percent of given sample of oxygen gas when raised to a high temperature dissociates into atoms. Ratio of its initial heat capacity (at constant volume) to its final heat capacity (at constant volume) will be