50278 + Interview Questions in Physics

1.	The acceleration of a cart started at t =0, varies with time as shown in figure (3-E2). Find the distance travelled in 30 seconds draw the position-tome graph.
Answer» The acceleration of a cart started at t =0, varies with time as shown in figure (3-E2). Find the distance travelled in 30 seconds draw the position-tome graph.

Discussion

2.	A boat of length 10 m and mass 450 kg is floating without motion in still water. A man of mass 50 kg standing at one end of it walks to the other end of it and stops. The magnitude of the displacement of the boat (in metre) relative to ground is
Answer» A boat of length $10 m$ and mass $450 kg$ is floating without motion in still water. A man of mass $50 kg$ standing at one end of it walks to the other end of it and stops. The magnitude of the displacement of the boat (in $metre$ ) relative to ground is

Discussion

3.	Three blocks of masses 2 kg, 4 kg and 6 kg arranged as shown in figure connected by string on a frictionless incline of 37∘. A force of 120 N is applied upward along the incline to the uppermost block. The cords are light. The tensions T1 and T2 in the strings are (g=10 m/s2, sin37∘=35)
Answer» Three blocks of masses $2 kg$ , $4 kg$ and $6 kg$ arranged as shown in figure connected by string on a frictionless incline of $37^{\circ}$ . A force of $120 N$ is applied upward along the incline to the uppermost block. The cords are light. The tensions $T_{1}$ and $T_{2}$ in the strings are $(g = 10 {m/s}^{2}, sin 37^{\circ} = \frac{3}{5})$

Discussion

4.	An inductor coil stores U energy when I current is passed through it and dissipates energy at the rate of P.Find the time cons†an t of the circuit ,when this coil is connected across a battery of zero internal resis†an ce
Answer» An inductor coil stores U energy when I current is passed through it and dissipates energy at the rate of P.Find the time cons†an t of the circuit ,when this coil is connected across a battery of zero internal resis†an ce

Discussion

5.	38.Two disc of moments of inertia I1 and I2 about their respective axes (normal to the disc and passing through the center),and rotating with angular speed omega 1 and omega2 are brought into contact face to face with their axes of rotation coincident . What is the loss in kinetic energy of the system in the process?
Answer» 38.Two disc of moments of inertia I1 and I2 about their respective axes (normal to the disc and passing through the center),and rotating with angular speed omega 1 and omega2 are brought into contact face to face with their axes of rotation coincident . What is the loss in kinetic energy of the system in the process?

Discussion

6.	A particle performs SHM with a period T and amplitude A. The mean velocity of the particle over the time interval during which it travels a distance A2 from the extreme position is
Answer» A particle performs SHM with a period $T$ and amplitude $A$ . The mean velocity of the particle over the time interval during which it travels a distance $\frac{A}{2}$ from the extreme position is

Discussion

7.	What is the difference between the symbol for speed and the symbol for velocity?
Answer» What is the difference between the symbol for speed and the symbol for velocity?

Discussion

8.	Supposethat the particle in Exercise in 1.33 is an electron projected withvelocity vx= 2.0 × 106m s−1.If E betweenthe plates separated by 0.5 cm is 9.1 × 102N/C, where will the electron strike the upper plate? (\| e\| =1.6 × 10−19C, me= 9.1 × 10−31kg.)
Answer» Suppose that the particle in Exercise in 1.33 is an electron projected with velocity v_x= 2.0 × 10⁶ m s⁻¹. If E between the plates separated by 0.5 cm is 9.1 × 10² N/C, where will the electron strike the upper plate? (\| e \| =1.6 × 10⁻¹⁹ C, m_e= 9.1 × 10⁻³¹ kg.)

Discussion

9.	The area of cross section of a current carrying conductor is A0 and A04 at section (1) and (2) respectively. If v1 and v2 are the drift velocity of region (1) and (2) respectively then
Answer» The area of cross section of a current carrying conductor is $A_{0}$ and $\frac{A_{0}}{4}$ at section $(1)$ and $(2)$ respectively. If $v_{1}$ and $v_{2}$ are the drift velocity of region $(1)$ and $(2)$ respectively then

Discussion

10.	39.A string of mass m is tied to a string and lowered at constant acceleration of g/2,through a distance d the work done by string will be
Answer» 39.A string of mass m is tied to a string and lowered at constant acceleration of g/2,through a distance d the work done by string will be

Discussion

11.	For a certain metal the K absorption edge is at 0.172 \overset0A. The wavelength of lines of K_α,K_β, and K_γ lines of K series are 0.210\overset oA, 0.192 \overset oA and 0.180\overset oA respectively. The energies of K, L and M Orbits are E_k, E_L and E_M respectively. Then, (a) E_K= -13.04keV (b) E_L= -7.52keV (c) E_M= -3.21keV (d) E_K= 13.04keV
Answer» For a certain metal the K absorption edge is at 0.172 \overset0A. The wavelength of lines of K_α,K_β, and K_γ lines of K series are 0.210\overset oA, 0.192 \overset oA and 0.180\overset oA respectively. The energies of K, L and M Orbits are E_k, E_L and E_M respectively. Then, (a) E_K= -13.04keV (b) E_L= -7.52keV (c) E_M= -3.21keV (d) E_K= 13.04keV

Discussion

12.	A swimmer wishes to cross a 500 m wide river flowing at 5 km/h. His speed with respect to water is 3 km/h. (a) If he heads in a direction making an angle (\theta\) with the flow, find the time he takes to cross the river. (b) Find the shortest possible time to cross the river.
Answer» A swimmer wishes to cross a 500 m wide river flowing at 5 km/h. His speed with respect to water is 3 km/h. (a) If he heads in a direction making an angle (\theta\) with the flow, find the time he takes to cross the river. (b) Find the shortest possible time to cross the river.

12.

A swimmer wishes to cross a 500 m wide river flowing at 5 km/h. His speed with respect to water is 3 km/h. (a) If he heads in a direction making an angle (\theta\) with the flow, find the time he takes to cross the river. (b) Find the shortest possible time to cross the river.

Answer»

A swimmer wishes to cross a 500 m wide river flowing at 5 km/h. His speed with respect to water is 3 km/h.

(a) If he heads in a direction making an angle (\theta\) with the flow, find the time he takes to cross the river.

(b) Find the shortest possible time to cross the river.

Discussion

13.	3 moles of an ideal monoatomic gas perfoms a cycle shown in the figure. The gas temperature at A,B,C,D are TA=400 K, TB=800 K,TC=2400 K,TD=1200 K. Find the work done by the gas.
Answer» $3$ moles of an ideal monoatomic gas perfoms a cycle shown in the figure. The gas temperature at $A, B, C, D$ are $T_{A} = 400 K,$ $T_{B} = 800 K, T_{C} = 2400 K, T_{D} = 1200 K .$ Find the work done by the gas.

Discussion

14.	A police Jeep is chasing with velocity of 45 km/hr a thief in another Jeep moving with velocity 153km/hr . Police fires a bullet with nozzle velocity of 180m/s . The velocity with which it will strike the car of thief is
Answer» A police Jeep is chasing with velocity of 45 km/hr a thief in another Jeep moving with velocity 153km/hr . Police fires a bullet with nozzle velocity of 180m/s . The velocity with which it will strike the car of thief is

Discussion

15.	() A square plate has a moment of inertiaaxis lying in its plane, passing through its centreand making an angle θ with one of the sides. Whichgraph represents the variation of / with theta?explain
Answer» () A square plate has a moment of inertiaaxis lying in its plane, passing through its centreand making an angle θ with one of the sides. Whichgraph represents the variation of / with theta?explain

Discussion

16.	Two towns A and B are connected to a regular bus service with a bus leaving in either direction every T min. A man cycling with a speed of 20 km/hr in the direction A to B notices that a bus goes past him every 18 min in the direction of his motion, and in every 6 min in the opposite direction. What is the period T of the bus service and with what speed do the bus ply on the road?
Answer» Two towns A and B are connected to a regular bus service with a bus leaving in either direction every T min. A man cycling with a speed of 20 km/hr in the direction A to B notices that a bus goes past him every 18 min in the direction of his motion, and in every 6 min in the opposite direction. What is the period T of the bus service and with what speed do the bus ply on the road?

Discussion

17.	A force of 6.4 N stretches a vertical spring by 0.1 m. The mass that must be suspended from the spring so that it oscillates with a period of pi/4 sec is how much
Answer» A force of 6.4 N stretches a vertical spring by 0.1 m. The mass that must be suspended from the spring so that it oscillates with a period of pi/4 sec is how much

Discussion

18.	The potential energy of a particle of mass m at a distance r from a fixed point O is given by V(r)=kr2/2 , where k is a positive constant of appropriate dimensions. This particle is moving in a circular orbit of radius R about the point O. If v is the speed of the particle and L is the magnitude of its angular momentum about O, which of the following statements is (are) true?
Answer» The potential energy of a particle of mass $m$ at a distance $r$ from a fixed point $O$ is given by $V (r) = k r^{2} / 2$ , where $k$ is a positive constant of appropriate dimensions. This particle is moving in a circular orbit of radius $R$ about the point $O$ . If $v$ is the speed of the particle and $L$ is the magnitude of its angular momentum about $O$ , which of the following statements is (are) true?

Discussion

19.	A normal is drawn at a point (x1,y1) of the parabola y2=16x and this normal makes equal angle with both x and y axes. Then point (x1,y1) is
Answer» A normal is drawn at a point $(x_{1}, y_{1})$ of the parabola $y^{2} = 16 x$ and this normal makes equal angle with both $x$ and $y$ axes. Then point $(x_{1}, y_{1})$ is

Discussion

20.	There are two conducting spheres of radius a andb(b> a) carrying equal and opposite charges. Theyare placed at a separation d (>> a andcapacitance of system is
Answer» There are two conducting spheres of radius a andb(b> a) carrying equal and opposite charges. Theyare placed at a separation d (>> a andcapacitance of system is

Discussion

21.	A small block starts slipping down from a point B on an inclined plane AB, which is making an angle θ with the horizontal, section BC is smooth, and the remaining section CA is rough with a coefficient of friction μ. It is found that the block comes to rest as it reaches the bottom (point A) of the inclined plane. If BC=2AC, the coefficient of friction is given by μ=ktanθ. The value of k is
Answer» A small block starts slipping down from a point $B$ on an inclined plane $A B$ , which is making an angle $θ$ with the horizontal, section $B C$ is smooth, and the remaining section $C A$ is rough with a coefficient of friction $μ$ . It is found that the block comes to rest as it reaches the bottom $(point A)$ of the inclined plane. If $B C = 2 A C$ , the coefficient of friction is given by $μ = k tan θ$ . The value of $k$ is

Discussion

22.	A body slides down an inclined plane of inclination θ.The coefficient of friction down the plane varies as μ=α x. Here, α is a positive constant and x is the distance moved by the body down the plane. The kinetic energy (K) versus distance (x) graph will be as
Answer» A body slides down an inclined plane of inclination $θ$ . The coefficient of friction down the plane varies as $μ = α x .$ Here, $α$ is a positive constant and x is the distance moved by the body down the plane. The kinetic energy (K) versus distance (x) graph will be as

Discussion

23.	A cubical block of side 'a' moving on horizontal frictionless surface with velocity 'v' hits a small nail [coefficient of restitution is e = 0] and rotates about it. Angular velocity of block after hitting the nail is
Answer» A cubical block of side ' $a$ ' moving on horizontal frictionless surface with velocity ' $v$ ' hits a small nail [coefficient of restitution is e = 0] and rotates about it. Angular velocity of block after hitting the nail is

Discussion

24.	A boy is moving unidirectionally under the influence of constant power source. Its displacement in time 't' is proportional to
Answer» A boy is moving unidirectionally under the influence of constant power source. Its displacement in time ' $t$ ' is proportional to

Discussion

25.	A block of mass 2 kg is moving with speed v0 towards a massless unstreched spring (K=10 N/m). It is found that for maximum speed v0=√6.4 m/s, the block compresses the spring, stops at that position and does not return back. Friction coefficient at surface is μ=1x. Value of x is ___
Answer» A block of mass 2 kg is moving with speed $v_{0}$ towards a massless unstreched spring (K=10 N/m). It is found that for maximum speed $v_{0} = \sqrt{6.4} m / s$ , the block compresses the spring, stops at that position and does not return back. Friction coefficient at surface is $μ = \frac{1}{x}$ . Value of x is ___

Discussion

26.	A plane electromagnetic wave is propagating in the x−direction, has a wavelength of 5 mm. The electric field is in the y−direction and its maximum magnitude is 30 V/m. The possible equation for the associated magnetic field is -
Answer» A plane electromagnetic wave is propagating in the $x -$ direction, has a wavelength of $5 mm$ . The electric field is in the $y -$ direction and its maximum magnitude is $30 V/m$ . The possible equation for the associated magnetic field is -

Discussion

27.	An X-ray photon of wavelength λ and frequency v collides with an electron and bounces off. If λ′ and v′ are respectively the wavelength and frequency of the scattered photon, then
Answer» An X-ray photon of wavelength $λ$ and frequency $v$ collides with an electron and bounces off. If $λ^{'}$ and $v^{'}$ are respectively the wavelength and frequency of the scattered photon, then

Discussion

28.	define time of flight (Tf) and write the expression for it
Answer» define time of flight (Tf) and write the expression for it

Discussion

29.	A wooden block of mass ‘M’ resting on a rough horizontal floor is pulled with a force ‘F’ at an angle ϕ with the horizontal. If μ is coefficient of kinetic friction between the block and the surface then acceleration of the block
Answer» A wooden block of mass ‘M’ resting on a rough horizontal floor is pulled with a force ‘F’ at an angle $ϕ$ with the horizontal. If $μ$ is coefficient of kinetic friction between the block and the surface then acceleration of the block

Discussion

30.	Ekample 8. A current of 1.0 A is flowing in the sides of anequilateral triangle of side 4.5 x 10-2field at the centroid of the triangle.7m. Find the magnetic[Roorkee 91]
Answer» Ekample 8. A current of 1.0 A is flowing in the sides of an equilateral triangle of side 4.5 x 10-2 field at the centroid of the triangle. 7 m. Find the magnetic [Roorkee 91]

Discussion

31.	The current in the winding of a toroid is 2.0 A. There are 400 turns and the mean circumferential length is 40 cm. If the magnetic field inside the toroid is 0.5 T, the permeability is nearly:
Answer» The current in the winding of a toroid is $2.0 A$ . There are $400$ turns and the mean circumferential length is $40 cm$ . If the magnetic field inside the toroid is $0.5 T$ , the permeability is nearly:

Discussion

32.	30. Consider a system consisting of two equal masses tied by massless string placed over a wedge such that string passes over a frictionless pulley then determine acceleration of centre of mass
Answer» 30. Consider a system consisting of two equal masses tied by massless string placed over a wedge such that string passes over a frictionless pulley then determine acceleration of centre of mass

Discussion

33.	A 15 g bullet is fired horizontally at a speed of 350 m/s into 1.2 kg block that hangs by a vertical string as shown below. The bullet remains embedded in the block. Find the speed of the bullet and the block.
Answer» A $15 g$ bullet is fired horizontally at a speed of $350 m/s$ into $1.2 kg$ block that hangs by a vertical string as shown below. The bullet remains embedded in the block. Find the speed of the bullet and the block.

Discussion

34.	A disc is given velocity V and angular velocity ω [where V = 2Rω] on a surface with friction as shown in the figure. After what time will the friction on the disc become zero?
Answer» A disc is given velocity V and angular velocity $ω$ [where V = 2R $ω$ ] on a surface with friction as shown in the figure. After what time will the friction on the disc become zero?

Discussion

35.	A point mass m is placed at a distance R from the surface of a solid sphere of mass m and radius R. The gravitational potential energy of this system of point mass and sphere
Answer» A point mass m is placed at a distance R from the surface of a solid sphere of mass m and radius R. The gravitational potential energy of this system of point mass and sphere

Discussion

36.	In 1.0 s, a particle goes from point A to point B, moving in a semicircle of radius 1.0 m (see figure). The magnitude of the average velocity is
Answer» In 1.0 s, a particle goes from point A to point B, moving in a semicircle of radius 1.0 m (see figure). The magnitude of the average velocity is

Discussion

37.	If the ratio of forces on both sides of a hydraulic jack is 1:40, then what is the ratio of the area of both sides?
Answer» If the ratio of forces on both sides of a hydraulic jack is $1 : 40$ , then what is the ratio of the area of both sides?

Discussion

38.	A cube of side b has a charge q at each of its vertices. Determine the potential and electric field due to this charge array at the centre of the cube.
Answer» A cube of side b has a charge q at each of its vertices. Determine the potential and electric field due to this charge array at the centre of the cube.

Discussion

39.	When the light hits a polishied surface then the light reflect back, then Lens are also polishied smoothly then why does it allow the light to pass through it,the lens should also reflect the light right?
Answer» When the light hits a polishied surface then the light reflect back, then Lens are also polishied smoothly then why does it allow the light to pass through it,the lens should also reflect the light right?

Discussion

40.	A 12 Ω resistance and an inductance of 0.05π H with negligible resistance are connected in series. Across the ends of this circuit a 130 V alternating voltage of frequency 50 Hz is connected. Calculate the alternating current in the circuit and the potential difference across the resistance.
Answer» A $12 Ω$ resistance and an inductance of $\frac{0.05}{π} H$ with negligible resistance are connected in series. Across the ends of this circuit a $130 V$ alternating voltage of frequency $50 Hz$ is connected. Calculate the alternating current in the circuit and the potential difference across the resistance.

Discussion

41.	The van der Waals' equation for (12) mole of a gas is:
Answer» The van der Waals' equation for $(\frac{1}{2})$ mole of a gas is:

Discussion

42.	An angle ∠AOB=θ made of a conducting wire of length l, moves with speed u along its angle bisector through a magnetic field B as shown. Find the induced emf between the two free ends if the magnetic field B is perpendicular to the plane.
Answer» An angle $∠ A O B = θ$ made of a conducting wire of length $l$ , moves with speed $u$ along its angle bisector through a magnetic field $B$ as shown. Find the induced emf between the two free ends if the magnetic field $B$ is perpendicular to the plane.

Discussion

43.	a coil o inductive reactance 31 ohm has a resistance o 8 ohm . It is placed in series with a condenser o capacitive reactance 25 ohm. the combination is connected to an AC source o 110 V . the power actor o the circuit is
Answer» a coil o inductive reactance 31 ohm has a resistance o 8 ohm . It is placed in series with a condenser o capacitive reactance 25 ohm. the combination is connected to an AC source o 110 V . the power actor o the circuit is

Discussion

44.	Consider two identical springs each of spring constant k and negligible mass as compared to the mass M are as shown in the figure. Figure 1 shows one of them connected to mass M and Figure 2 shows their series combination connected to the same mass. The ratio of time period of oscillation of the two SHM is TbTa=√x, where value of x is ______.(Round off to the nearest integer)
Answer» Consider two identical springs each of spring constant $k$ and negligible mass as compared to the mass $M$ are as shown in the figure. Figure $1$ shows one of them connected to mass $M$ and Figure $2$ shows their series combination connected to the same mass. The ratio of time period of oscillation of the two $S H M$ is $\frac{T_{b}}{T_{a}} = \sqrt{x}$ , where value of $x$ is ______. $($ Round off to the nearest integer $)$

Discussion

45.	Ball 1 collides head on with another identical ball 2, initially at rest. Velocity of ball 2 after collision becomes two times that of ball 1 after collision. The coefficient of restitution between the two balls is :
Answer» Ball $1$ collides head on with another identical ball $2$ , initially at rest. Velocity of ball $2$ after collision becomes two times that of ball $1$ after collision. The coefficient of restitution between the two balls is :

Discussion

46.	Comprehension :A 100 Ω resistance is connected in series with a 4 H inductor. The voltage across the resistor is, VR=2.0sin(103t) V.(ii) Find the inductive reactance-
Answer» Comprehension : A $100 Ω$ resistance is connected in series with a $4 H$ inductor. The voltage across the resistor is, $V_{R} = 2.0 sin (10^{3} t) V .$ $(i i)$ Find the inductive reactance-

Discussion

47.	Consider steady-state heat conduction across the thickness in a plane composite wall (as shown in the figure) exposed to convection conditions on both sides.Given :hi=20 W/m2K; h∘=50 W/m2K; T∞,i=20∘C, T∞,∘=−2∘Ck1=20 W/mK; k2=50 W/mK;L1=0.30 m and L2=0.15 mAssuming negligible contact resistance between the wall surfaces, the interface temperature, T(in ∘ C), of the two walls will be
Answer» Consider steady-state heat conduction across the thickness in a plane composite wall (as shown in the figure) exposed to convection conditions on both sides. Given : $h_{i} = 20 W / m^{2} K; h_{\circ} = 50 W / m^{2} K; T_{\infty, i} = 20^{\circ} C, T_{\infty, \circ} = - 2^{\circ} C k_{1} = 20 W / m K; k_{2} = 50 W / m K; L_{1} = 0.30 m a n d L_{2} = 0.15 m$ Assuming negligible contact resistance between the wall surfaces, the interface temperature, $T (i n^{\circ} C),$ of the two walls will be

Discussion

48.	A raindrop with radius R=0.2 mm falls from a cloud at a height h=2000 m above the ground. Assume that the drop is spherical throughout its fall and the force of buoyance may be neglected, then the terminal speed attained by the raindrop is :[Density of water ρw=1000 kg m−3 and density of air ρa=1.2 kg m−3,g=10 m/s2Coefficient of viscosity of air=1.8×10−5 Nsm−2
Answer» A raindrop with radius $R = 0.2 mm$ falls from a cloud at a height $h = 2000 m$ above the ground. Assume that the drop is spherical throughout its fall and the force of buoyance may be neglected, then the terminal speed attained by the raindrop is : [Density of water $ρ_{w} = 1000 {kg m}^{- 3}$ and density of air $ρ_{a} = 1.2 {kg m}^{- 3}, g = 10 {m/s}^{2}$ Coefficient of viscosity of air $= 1.8 \times 10^{- 5} {Nsm}^{- 2}$

Discussion

49.	An electron beam undergo diffraction by crystals. Though what potential should a beam of electrons be accelerated so that its wavelength is equal to 1.6A^° 1) 58.90 V 2) 85.75 V 3)45.35 V 4) 105.31 V
Answer» An electron beam undergo diffraction by crystals. Though what potential should a beam of electrons be accelerated so that its wavelength is equal to 1.6A^° 1) 58.90 V 2) 85.75 V 3)45.35 V 4) 105.31 V

Discussion

50.	Under standard conditions the gas density is 1.3 mgcm3 and the velocity of sound propagation in it is 330 ms, then the number of degrees of freedom of gas is.
Answer» Under standard conditions the gas density is 1.3 $\frac{m g}{c m^{3}}$ and the velocity of sound propagation in it is 330 $\frac{m}{s}$ , then the number of degrees of freedom of gas is.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The acceleration of a cart started at t =0, varies with time as shown in figure (3-E2). Find the distance travelled in 30 seconds draw the position-tome graph.

A boat of length 10 m and mass 450 kg is floating without motion in still water. A man of mass 50 kg standing at one end of it walks to the other end of it and stops. The magnitude of the displacement of the boat (in metre) relative to ground is

Three blocks of masses 2 kg, 4 kg and 6 kg arranged as shown in figure connected by string on a frictionless incline of 37∘. A force of 120 N is applied upward along the incline to the uppermost block. The cords are light. The tensions T1 and T2 in the strings are (g=10 m/s2, sin37∘=35)

An inductor coil stores U energy when I current is passed through it and dissipates energy at the rate of P.Find the time cons†an t of the circuit ,when this coil is connected across a battery of zero internal resis†an ce

A particle performs SHM with a period T and amplitude A. The mean velocity of the particle over the time interval during which it travels a distance A2 from the extreme position is

What is the difference between the symbol for speed and the symbol for velocity?

Supposethat the particle in Exercise in 1.33 is an electron projected withvelocity vx= 2.0 × 106m s−1.If E betweenthe plates separated by 0.5 cm is 9.1 × 102N/C, where will the electron strike the upper plate? (| e| =1.6 × 10−19C, me= 9.1 × 10−31kg.)

The area of cross section of a current carrying conductor is A0 and A04 at section (1) and (2) respectively. If v1 and v2 are the drift velocity of region (1) and (2) respectively then

39.A string of mass m is tied to a string and lowered at constant acceleration of g/2,through a distance d the work done by string will be

A swimmer wishes to cross a 500 m wide river flowing at 5 km/h. His speed with respect to water is 3 km/h. (a) If he heads in a direction making an angle (\theta\) with the flow, find the time he takes to cross the river. (b) Find the shortest possible time to cross the river.

3 moles of an ideal monoatomic gas perfoms a cycle shown in the figure. The gas temperature at A,B,C,D are TA=400 K, TB=800 K,TC=2400 K,TD=1200 K. Find the work done by the gas.

A police Jeep is chasing with velocity of 45 km/hr a thief in another Jeep moving with velocity 153km/hr . Police fires a bullet with nozzle velocity of 180m/s . The velocity with which it will strike the car of thief is

() A square plate has a moment of inertiaaxis lying in its plane, passing through its centreand making an angle θ with one of the sides. Whichgraph represents the variation of / with theta?explain

A force of 6.4 N stretches a vertical spring by 0.1 m. The mass that must be suspended from the spring so that it oscillates with a period of pi/4 sec is how much

A normal is drawn at a point (x1,y1) of the parabola y2=16x and this normal makes equal angle with both x and y axes. Then point (x1,y1) is

There are two conducting spheres of radius a andb(b> a) carrying equal and opposite charges. Theyare placed at a separation d (>> a andcapacitance of system is

A body slides down an inclined plane of inclination θ.The coefficient of friction down the plane varies as μ=α x. Here, α is a positive constant and x is the distance moved by the body down the plane. The kinetic energy (K) versus distance (x) graph will be as

A cubical block of side 'a' moving on horizontal frictionless surface with velocity 'v' hits a small nail [coefficient of restitution is e = 0] and rotates about it. Angular velocity of block after hitting the nail is

A boy is moving unidirectionally under the influence of constant power source. Its displacement in time 't' is proportional to

A block of mass 2 kg is moving with speed v0 towards a massless unstreched spring (K=10 N/m). It is found that for maximum speed v0=√6.4 m/s, the block compresses the spring, stops at that position and does not return back. Friction coefficient at surface is μ=1x. Value of x is ___

A plane electromagnetic wave is propagating in the x−direction, has a wavelength of 5 mm. The electric field is in the y−direction and its maximum magnitude is 30 V/m. The possible equation for the associated magnetic field is -

An X-ray photon of wavelength λ and frequency v collides with an electron and bounces off. If λ′ and v′ are respectively the wavelength and frequency of the scattered photon, then

define time of flight (Tf) and write the expression for it

A wooden block of mass ‘M’ resting on a rough horizontal floor is pulled with a force ‘F’ at an angle ϕ with the horizontal. If μ is coefficient of kinetic friction between the block and the surface then acceleration of the block

Ekample 8. A current of 1.0 A is flowing in the sides of anequilateral triangle of side 4.5 x 10-2field at the centroid of the triangle.7m. Find the magnetic[Roorkee 91]

The current in the winding of a toroid is 2.0 A. There are 400 turns and the mean circumferential length is 40 cm. If the magnetic field inside the toroid is 0.5 T, the permeability is nearly:

30. Consider a system consisting of two equal masses tied by massless string placed over a wedge such that string passes over a frictionless pulley then determine acceleration of centre of mass

A 15 g bullet is fired horizontally at a speed of 350 m/s into 1.2 kg block that hangs by a vertical string as shown below. The bullet remains embedded in the block. Find the speed of the bullet and the block.

A disc is given velocity V and angular velocity ω [where V = 2Rω] on a surface with friction as shown in the figure. After what time will the friction on the disc become zero?

A point mass m is placed at a distance R from the surface of a solid sphere of mass m and radius R. The gravitational potential energy of this system of point mass and sphere

In 1.0 s, a particle goes from point A to point B, moving in a semicircle of radius 1.0 m (see figure). The magnitude of the average velocity is

If the ratio of forces on both sides of a hydraulic jack is 1:40, then what is the ratio of the area of both sides?

A cube of side b has a charge q at each of its vertices. Determine the potential and electric field due to this charge array at the centre of the cube.

When the light hits a polishied surface then the light reflect back, then Lens are also polishied smoothly then why does it allow the light to pass through it,the lens should also reflect the light right?

A 12 Ω resistance and an inductance of 0.05π H with negligible resistance are connected in series. Across the ends of this circuit a 130 V alternating voltage of frequency 50 Hz is connected. Calculate the alternating current in the circuit and the potential difference across the resistance.

The van der Waals' equation for (12) mole of a gas is:

An angle ∠AOB=θ made of a conducting wire of length l, moves with speed u along its angle bisector through a magnetic field B as shown. Find the induced emf between the two free ends if the magnetic field B is perpendicular to the plane.

a coil o inductive reactance 31 ohm has a resistance o 8 ohm . It is placed in series with a condenser o capacitive reactance 25 ohm. the combination is connected to an AC source o 110 V . the power actor o the circuit is

Ball 1 collides head on with another identical ball 2, initially at rest. Velocity of ball 2 after collision becomes two times that of ball 1 after collision. The coefficient of restitution between the two balls is :

Comprehension :A 100 Ω resistance is connected in series with a 4 H inductor. The voltage across the resistor is, VR=2.0sin(103t) V.(ii) Find the inductive reactance-

An electron beam undergo diffraction by crystals. Though what potential should a beam of electrons be accelerated so that its wavelength is equal to 1.6A^° 1) 58.90 V 2) 85.75 V 3)45.35 V 4) 105.31 V

Under standard conditions the gas density is 1.3 mgcm3 and the velocity of sound propagation in it is 330 ms, then the number of degrees of freedom of gas is.