50278 + Interview Questions in Physics

1.	A particle travels along the x-axis. Its velocity time graph is shown above. What is the total displacement of the particle at t = 20 sec?
Answer» A particle travels along the x-axis. Its velocity time graph is shown above. What is the total displacement of the particle at t = 20 sec?

1.

A particle travels along the x-axis. Its velocity time graph is shown above. What is the total displacement of the particle at t = 20 sec?

Answer»

A particle travels along the x-axis. Its velocity time graph is shown above.

What is the total displacement of the particle at t = 20 sec?

2.	Q9. A, B, C, D and E when arranged in descending order of their weight (from top), A becomes third, E is between D and A. C and D are not at the top. Who among them is the second?
Answer» Q9. A, B, C, D and E when arranged in descending order of their weight (from top), A becomes third, E is between D and A. C and D are not at the top. Who among them is the second?

Discussion

3.	A ball is thrown up from the top of a tower with 20 m/s velocity. It took the ball 6 sec to fall to the bottom. How much distance did the ball cover in the last second of its motion?
Answer» A ball is thrown up from the top of a tower with 20 m/s velocity. It took the ball 6 sec to fall to the bottom. How much distance did the ball cover in the last second of its motion?

Discussion

4.	Q. Two spherical raindrops of equal size are falling vertically through air with a terminal velocity of 1m/s. What would be the terminal speed if these two drops were to coalesce to form a larger spherical drop.
Answer» Q. Two spherical raindrops of equal size are falling vertically through air with a terminal velocity of 1m/s. What would be the terminal speed if these two drops were to coalesce to form a larger spherical drop.

Discussion

5.	A 1000kg automobile is moving along a straight highway at 10$ms^{-1}$. Another car with mass 2000kg and speed 20$ms^{-1}$ is 30m ahead of the first. The position of the centre of mass of the system from the first is
Answer» A 1000kg automobile is moving along a straight highway at 10$ms^{-1}$. Another car with mass 2000kg and speed 20$ms^{-1}$ is 30m ahead of the first. The position of the centre of mass of the system from the first is

Discussion

6.	A machine gun fires a bullet of mass 40 g with a velocity 12 m/ s . The man holding it can exert a maximum force of 144 N on the gun . How many bullets can he fire per second at the most ?
Answer» A machine gun fires a bullet of mass 40 g with a velocity 12 m/ s . The man holding it can exert a maximum force of 144 N on the gun . How many bullets can he fire per second at the most ?

Discussion

7.	When a particle moves in a uniform circular motion. It has
Answer» When a particle moves in a uniform circular motion. It has

Discussion

8.	If surface area of a cube is changing at a rate of 5 m2/s , find the rate at which length of the body diagonal changes, at a moment when side length is 1 m.
Answer» If surface area of a cube is changing at a rate of $5 m^{2} / s$ , find the rate at which length of the body diagonal changes, at a moment when side length is $1 m$ .

Discussion

9.	The resistance of a wire is r ohms. It is stretched to double its length. The new resistance of the wire in ohms is
Answer» The resistance of a wire is r ohms. It is stretched to double its length. The new resistance of the wire in ohms is

Discussion

10.	A transparent solid cylindrical rod has a refractive index of 2√3. It is surrounded by air. A light ray is incident at the mid point of one end of the rod as shown in the figure. The incident angle θ for which the light ray grazes along the wall of the rod is
Answer» A transparent solid cylindrical rod has a refractive index of $\frac{2}{\sqrt{3}} .$ It is surrounded by air. A light ray is incident at the mid point of one end of the rod as shown in the figure. The incident angle $θ$ for which the light ray grazes along the wall of the rod is

Discussion

11.	In a Young’s double slit experiment, let I0 be the intensity at the central maximum and β be the fringe width. Then intensity at a point P which is at a distance x from the central maximum is
Answer» In a Young’s double slit experiment, let $I_{0}$ be the intensity at the central maximum and $β$ be the fringe width. Then intensity at a point $P$ which is at a distance $x$ from the central maximum is

Discussion

12.	A pendulum with its two extreme points at (5, 12) and (12, 5) is oscillating about the origin at constant angular velocity of 180∘/sec. Find the period of pendulum (Approximate value)
Answer» A pendulum with its two extreme points at (5, 12) and (12, 5) is oscillating about the origin at constant angular velocity of $180^{\circ}$ /sec. Find the period of pendulum (Approximate value)

Discussion

13.	A person can spin a grindstone of radius 0.32 m by placing his hand on its edge through a part of revolution. If the force of 200 N is applied perpendicular to the grindstone on its outer surface, the work done by the force through a rotation of 1 rad is
Answer» A person can spin a grindstone of radius 0.32 m by placing his hand on its edge through a part of revolution. If the force of 200 N is applied perpendicular to the grindstone on its outer surface, the work done by the force through a rotation of 1 rad is

Discussion

14.	STATEMENT-1 - A point particle of mass m moving with speed v collides with stationary point particle of mass M. If the max energy loss possible is given as f(mv2/2), then f=(m/M+m). STATEMENT-2 - Max energy loss occurs when the particles get stuck together as a result of the collision. A) Both S1 and S2 are true, S2 explains S1 correctly B) Both S1 and S2 are true, S2 does not explain S1 C) S2 is false, S1 is true D) S1 is false, S2 is true Explain in detail.
Answer» STATEMENT-1 - A point particle of mass m moving with speed v collides with stationary point particle of mass M. If the max energy loss possible is given as f(mv²/2), then f=(m/M+m). STATEMENT-2 - Max energy loss occurs when the particles get stuck together as a result of the collision. A) Both S1 and S2 are true, S2 explains S1 correctly B) Both S1 and S2 are true, S2 does not explain S1 C) S2 is false, S1 is true D) S1 is false, S2 is true Explain in detail.

14.

STATEMENT-1 - A point particle of mass m moving with speed v collides with stationary point particle of mass M. If the max energy loss possible is given as f(mv2/2), then f=(m/M+m). STATEMENT-2 - Max energy loss occurs when the particles get stuck together as a result of the collision. A) Both S1 and S2 are true, S2 explains S1 correctly B) Both S1 and S2 are true, S2 does not explain S1 C) S2 is false, S1 is true D) S1 is false, S2 is true Explain in detail.

Answer»

STATEMENT-1 - A point particle of mass m moving with speed v collides with stationary point particle of mass M. If the max energy loss possible is given as f(mv²/2), then f=(m/M+m).

STATEMENT-2 - Max energy loss occurs when the particles get stuck together as a result of the collision.

A) Both S1 and S2 are true, S2 explains S1 correctly

B) Both S1 and S2 are true, S2 does not explain S1

C) S2 is false, S1 is true

D) S1 is false, S2 is true

Explain in detail.

Discussion

15.	ABCD is a square of unit side. It is folded along the diagonal AC, so that the plane ABC is perpendicular to the plane ACD. The shortest distance between the lines AB and CD is
Answer» ABCD is a square of unit side. It is folded along the diagonal AC, so that the plane ABC is perpendicular to the plane ACD. The shortest distance between the lines AB and CD is

Discussion

16.	A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is 36∘ C. Then the difference of temperature at the two surfaces ofAwill be
Answer» A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is $36^{\circ} C$ . Then the difference of temperature at the two surfaces ofAwill be

16.

A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is 36∘ C. Then the difference of temperature at the two surfaces ofAwill be

Answer»

A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is $36^{\circ} C$ . Then the difference of temperature at the two surfaces ofAwill be

Discussion

17.	A uniform disc of mass M and radius R is mounted on an axle supported in frictionless bearings. A light cord is wrapped around the rim of the disc as shown in figure below. If we hang a body of mass m with the cord, it has acceleration a as shown in figure. Find the angular acceleration of the disc (α).
Answer» A uniform disc of mass $M$ and radius $R$ is mounted on an axle supported in frictionless bearings. A light cord is wrapped around the rim of the disc as shown in figure below. If we hang a body of mass $m$ with the cord, it has acceleration $a$ as shown in figure. Find the angular acceleration of the disc $(α)$ .

Discussion

18.	An alternating voltage V = 200 sin 100t, where V is in volt and t seconds, is connected to a series combination of 1μ farad capacitor and 10K Ω resistor through an AC ammeter. The reading of the ammeter will be
Answer» An alternating voltage V = 200 sin 100t, where V is in volt and t seconds, is connected to a series combination of 1 $μ$ farad capacitor and 10K $Ω$ resistor through an AC ammeter. The reading of the ammeter will be

Discussion

19.	In the figure, the blocks A,B, and C of mass m each have acceleration a1,a2, and a3 respectively. F1 and F2 are external forces of magnitude 2mg and mg respectively. Thena1=a2=a3a1>a3>a2a1=a2,a2>a3a1>a2,a2=a3
Answer» In the figure, the blocks $A, B,$ and $C$ of mass m each have acceleration $a_{1}, a_{2},$ and $a_{3}$ respectively. $F_{1}$ and $F_{2}$ are external forces of magnitude $2 m g$ and $m g$ respectively. Then $a_{1} = a_{2} = a_{3}$ $a_{1} > a_{3} > a_{2}$ $a_{1} = a_{2}, a_{2} > a_{3}$ $a_{1} > a_{2}, a_{2} = a_{3}$

19.

In the figure, the blocks A,B, and C of mass m each have acceleration a1,a2, and a3 respectively. F1 and F2 are external forces of magnitude 2mg and mg respectively. Thena1=a2=a3a1>a3>a2a1=a2,a2>a3a1>a2,a2=a3

Answer»

In the figure, the blocks $A, B,$ and $C$ of mass m each have acceleration $a_{1}, a_{2},$ and $a_{3}$ respectively. $F_{1}$ and $F_{2}$ are external forces of magnitude $2 m g$ and $m g$ respectively. Then

$a_{1} = a_{2} = a_{3}$
$a_{1} > a_{3} > a_{2}$
$a_{1} = a_{2}, a_{2} > a_{3}$
$a_{1} > a_{2}, a_{2} = a_{3}$

Discussion

20.	In the experiment on photoelectric effect, the graph between Emax and v is found to be straight line as shown in figure. The threshold frequency and Planck's constant according to this graph are
Answer» In the experiment on photoelectric effect, the graph between $E_{m a x}$ and $v$ is found to be straight line as shown in figure. The threshold frequency and Planck's constant according to this graph are

Discussion

21.	A body starts from the origin and moves along the X-axis such that the velocity at any instant is given by (4t3−2t), where t is in sec and velocity in m/s. What is the acceleration of the particle, when it is 2 m from the origin
Answer» A body starts from the origin and moves along the X-axis such that the velocity at any instant is given by $(4 t^{3} - 2 t)$ , where t is in sec and velocity in m/s. What is the acceleration of the particle, when it is 2 m from the origin

Discussion

22.	What is the average velocity of the coin?
Answer» What is the average velocity of the coin?

Discussion

23.	In the circuit shown in figure, find the current through the branch BD
Answer» In the circuit shown in figure, find the current through the branch BD

Discussion

24.	A particle free to move along the x-axis has potential energy given by U(x)=k[1−exp(−x)2] for −∞≤x≤+∞, where k is a positive constant of appropriate dimensions. Then
Answer» A particle free to move along the x-axis has potential energy given by $U (x) = k [1 - e x p (- x)^{2}]$ for $- \infty \leq x \leq + \infty$ , where k is a positive constant of appropriate dimensions. Then

24.

A particle free to move along the x-axis has potential energy given by U(x)=k[1−exp(−x)2] for −∞≤x≤+∞, where k is a positive constant of appropriate dimensions. Then

Answer»

A particle free to move along the x-axis has potential energy given by $U (x) = k [1 - e x p (- x)^{2}]$ for $- \infty \leq x \leq + \infty$ , where k is a positive constant of appropriate dimensions. Then

Discussion

25.	Two masses of 4 kg and 5 kg are connected by a string passing through a frictionless pulley and are kept on a frictionless table as shown in the figure. The acceleration of 5 kg mass is
Answer» Two masses of 4 kg and 5 kg are connected by a string passing through a frictionless pulley and are kept on a frictionless table as shown in the figure. The acceleration of 5 kg mass is

25.

Two masses of 4 kg and 5 kg are connected by a string passing through a frictionless pulley and are kept on a frictionless table as shown in the figure. The acceleration of 5 kg mass is

Answer»

Two masses of 4 kg and 5 kg are connected by a string passing through a frictionless pulley and are kept on a frictionless table as shown in the figure. The acceleration of 5 kg mass is

Discussion

26.	A block of mass 2 kg, placed on a long frictionless horizontal table, is pulled horizontally by a constant force F. It is found to move 10 m in the first 2 s. Find the magnitude of the force F.
Answer» A block of mass 2 kg, placed on a long frictionless horizontal table, is pulled horizontally by a constant force F. It is found to move 10 m in the first 2 s. Find the magnitude of the force F.

Discussion

27.	Three rods of the same dimension have thermal conductivities 3K, 2K and K. They are arranged as shown in fig. Given below, with their ends at 100o C, 50o C and 20o C. The temperature of their junction is
Answer» Three rods of the same dimension have thermal conductivities 3K, 2K and K. They are arranged as shown in fig. Given below, with their ends at $100^{o} C, 50^{o} C a n d 20^{o} C$ . The temperature of their junction is

Discussion

28.	A ball is released from the top of a tower of height h. It takes time T to reach the ground. What is the position of the ball (from the ground after time T/3)?
Answer» A ball is released from the top of a tower of height $h$ . It takes time $T$ to reach the ground. What is the position of the ball (from the ground after time $T / 3$ )?

Discussion

29.	Write the relation for the speed of electromagnetic waves and the amplitudes of electric and magnetic fields.
Answer» Write the relation for the speed of electromagnetic waves and the amplitudes of electric and magnetic fields.

Discussion

30.	An inductor of reactance 60 Ω, capacitor of reactance 30 Ω and resistor of resistance 40 Ω are connected in series across a source of emf V=100 sin628t. Find power loss in the circuit.
Answer» An inductor of reactance $60 Ω$ , capacitor of reactance $30 Ω$ and resistor of resistance $40 Ω$ are connected in series across a source of emf $V = 100 sin 628 t$ . Find power loss in the circuit.

Discussion

31.	A particle is suspended by thread of length l from a fixed point. If it is launched from the bottom with a horizontal speed of v=√5gl, then tension in the thread when the particle is at the topmost point
Answer» A particle is suspended by thread of length $l$ from a fixed point. If it is launched from the bottom with a horizontal speed of $v = \sqrt{5 g l}$ , then tension in the thread when the particle is at the topmost point

Discussion

32.	A small particle travelling with a velocity v collides elastically with a spherical body of equal mass radius r initially kept at rest.The centre of this spherical body is located a distance away from the direction of motion of the particle (given figure).Find the final velocities of the two particles.
Answer» A small particle travelling with a velocity v collides elastically with a spherical body of equal mass radius r initially kept at rest.The centre of this spherical body is located a distance away from the direction of motion of the particle (given figure).Find the final velocities of the two particles.

32.

A small particle travelling with a velocity v collides elastically with a spherical body of equal mass radius r initially kept at rest.The centre of this spherical body is located a distance away from the direction of motion of the particle (given figure).Find the final velocities of the two particles.

Answer»

A small particle travelling with a velocity v collides elastically with a spherical body of equal mass radius r initially kept at rest.The centre of this spherical body is located a distance away from the direction of motion of the particle (given figure).Find the final velocities of the two particles.

Discussion

33.	For configuration of media of permittivity ε0,ε,ε0 between parallel plates each of area A as shown in the figure; the equivalent capacitance is
Answer» For configuration of media of permittivity $ε_{0}, ε, ε_{0}$ between parallel plates each of area $A$ as shown in the figure; the equivalent capacitance is

Discussion

34.	The friction coefficient between a road and the tyre of a vehicle is 43 . Find the maximum incline the road may have so that once hard brakes are applied and the wheel starts skidding, the vehicle going down at a speed of 36 km/hr is stopped within 5 m.
Answer» The friction coefficient between a road and the tyre of a vehicle is $\frac{4}{3}$ . Find the maximum incline the road may have so that once hard brakes are applied and the wheel starts skidding, the vehicle going down at a speed of 36 km/hr is stopped within 5 m.

Discussion

35.	Sir/Ma'am, What is the exact difference between energy and work?
Answer» Sir/Ma'am, What is the exact difference between energy and work?

Discussion

36.	A body dropped from a height H reaches the ground with a speed of 1.2 √gH.Calculate the work doneby air-friction.
Answer» A body dropped from a height H reaches the ground with a speed of 1.2 $\sqrt{g H}$ .Calculate the work doneby air-friction.

Discussion

37.	n charged drops, each of radius r and charge q, coalesce to form a big drop of radius R and charge Q. If V is the electric potential and E is the electric field at the surface of a drop, then
Answer» $n$ charged drops, each of radius $r$ and charge $q$ , coalesce to form a big drop of radius $R$ and charge $Q$ . If $V$ is the electric potential and $E$ is the electric field at the surface of a drop, then

Discussion

38.	The velocity of a body depends on time according to equation V=20 + 0.1 t2. the body is undergoing
Answer» The velocity of a body depends on time according to equation V=20 + 0.1 $t^{2}$ . the body is undergoing

Discussion

39.	The equation of a simple harmonic progressive wave is given by y = 8sin (0.628x – 12.56t) where x and y are in cm and t is in second. Find the phase difference in degrees between two particles at a distance of 2.0cm apart at any instant.
Answer» The equation of a simple harmonic progressive wave is given by y = 8sin (0.628x – 12.56t) where x and y are in cm and t is in second. Find the phase difference in degrees between two particles at a distance of 2.0cm apart at any instant.

Discussion

40.	A curve on a highway has a radius of curvature 40 m. The curved road is banked at an angle of 45∘ with the horizontal. If the coefficient of static friction that the road provides is μs=0.20, what is the maximum permissible speed (in m/s) limit for vehicles travelling on the road? Obtain the answer as nearest integer value Useful data : g=10 m/s2 , √6=2.40
Answer» A curve on a highway has a radius of curvature $40 m$ . The curved road is banked at an angle of $45^{\circ}$ with the horizontal. If the coefficient of static friction that the road provides is $μ_{s} = 0.20$ , what is the maximum permissible speed (in $m/s$ ) limit for vehicles travelling on the road? Obtain the answer as nearest integer value Useful data : $g = 10 {m/s}^{2}$ , $\sqrt{6} = 2.40$

Discussion

41.	The ends of a metal rod are kept at temperatures θ1 and θ2 with θ2 > θ1. The rate of flow of heat along the rod is directly proportional to.
Answer» $T h e e n d s o f a m e t a l r o d a r e k e p t a t t e m p e r a t u r e s θ_{1} a n d θ_{2} w i t h θ_{2} > θ_{1} . T h e r a t e o f f l o w o f h e a t a l o n g t h e r o d i s d i r e c t l y p r o p o r t i o n a l t o .$

Discussion

42.	Block A and B shown in the figure are connected with a bar of negligible weight. A and B each has mass 170 kg, the coefficient of friction between A and the plane is 0.2 and that between B and the plane is 0.4 (g=10 ms−2) What is the total force of friction between the blocks and the plane? [Hint: tan−1(815)=28∘,cos28∘=0.883,sin28∘=0.469]
Answer» Block $A$ and $B$ shown in the figure are connected with a bar of negligible weight. $A$ and $B$ each has mass $170 kg$ , the coefficient of friction between $A$ and the plane is $0.2$ and that between $B$ and the plane is $0.4$ ( $g = 10 {ms}^{- 2}$ ) What is the total force of friction between the blocks and the plane? [Hint: ${tan}^{- 1} (\frac{8}{15}) = 28^{\circ}, cos 28^{\circ} = 0.883, sin 28^{\circ} = 0.469$ ]

Discussion

43.	According to Rutherford's model, what will be the kinetic energy of an electron of mass me at a distance r from the center of a Li++ ion? (The Lithium nucleus has three protons.)
Answer» According to Rutherford's model, what will be the kinetic energy of an electron of mass m_e at a distance r from the center of a Li⁺⁺ ion? (The Lithium nucleus has three protons.)

Discussion

44.	The peak value of an alternating e.m.f. E is given by E=E0cos ωt is 10 volts and its frequency is 50 Hz. At time t=1600sec, the instantaneous e.m.f. is
Answer» The peak value of an alternating e.m.f. E is given by $E = E_{0} c o s ω t$ is 10 volts and its frequency is 50 Hz. At time $t = \frac{1}{600} s e c,$ the instantaneous e.m.f. is

Discussion

45.	If a particle of mass m is moving in a horizontal circle of radius r with a centripetal force (−kr2), the total energy is
Answer» If a particle of mass m is moving in a horizontal circle of radius r with a centripetal force $(- \frac{k}{r^{2}})$ , the total energy is

Discussion

46.	Boyle's law holds for an ideal gas during
Answer» Boyle's law holds for an ideal gas during

46.

Boyle's law holds for an ideal gas during

Answer»

Boyle's law holds for an ideal gas during

Discussion

47.	The heat generated by radioactivity within the earth is conducted outward through the oceans. Assuming the average temperature gradient within the solid earth beneath the ocean to be 0.07∘C−1 and the average thermal conductivity 0.2calm−1s−1C−1, determine the rate of heat transfer per square meter. Radius of the earth = 6400 km. Further, determine the quantity of heat transferred through the earth's surface each day.
Answer» The heat generated by radioactivity within the earth is conducted outward through the oceans. Assuming the average temperature gradient within the solid earth beneath the ocean to be ${0.07}^{\circ} C^{- 1}$ and the average thermal conductivity $0.2 c a l m^{- 1} s^{- 1} C^{- 1}$ , determine the rate of heat transfer per square meter. Radius of the earth = 6400 km. Further, determine the quantity of heat transferred through the earth's surface each day.

Discussion

48.	Hairs of shaving brush cling together when it is removed from water due to
Answer» Hairs of shaving brush cling together when it is removed from water due to

Discussion

49.	A uniform solid sphere of mass M and radius a is surrounded symmetrically by a uniform thin spherical shell of equal mass and radius 2 a. the ratio of gravitational field at a distance 32 a froth the centre to 52 a from the centre is..
Answer» A uniform solid sphere of mass M and radius a is surrounded symmetrically by a uniform thin spherical shell of equal mass and radius 2 a. the ratio of gravitational field at a distance $\frac{3}{2}$ a froth the centre to $\frac{5}{2}$ a from the centre is..

Discussion

50.	Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then
Answer» Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then

50.

Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then

Answer»

Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A particle travels along the x-axis. Its velocity time graph is shown above. What is the total displacement of the particle at t = 20 sec?

Q9. A, B, C, D and E when arranged in descending order of their weight (from top), A becomes third, E is between D and A. C and D are not at the top. Who among them is the second?

A ball is thrown up from the top of a tower with 20 m/s velocity. It took the ball 6 sec to fall to the bottom. How much distance did the ball cover in the last second of its motion?

Q. Two spherical raindrops of equal size are falling vertically through air with a terminal velocity of 1m/s. What would be the terminal speed if these two drops were to coalesce to form a larger spherical drop.

A 1000kg automobile is moving along a straight highway at 10\(ms^{-1}\). Another car with mass 2000kg and speed 20\(ms^{-1}\) is 30m ahead of the first. The position of the centre of mass of the system from the first is

A machine gun fires a bullet of mass 40 g with a velocity 12 m/ s . The man holding it can exert a maximum force of 144 N on the gun . How many bullets can he fire per second at the most ?

When a particle moves in a uniform circular motion. It has

If surface area of a cube is changing at a rate of 5 m2/s , find the rate at which length of the body diagonal changes, at a moment when side length is 1 m.

The resistance of a wire is r ohms. It is stretched to double its length. The new resistance of the wire in ohms is

A transparent solid cylindrical rod has a refractive index of 2√3. It is surrounded by air. A light ray is incident at the mid point of one end of the rod as shown in the figure. The incident angle θ for which the light ray grazes along the wall of the rod is

In a Young’s double slit experiment, let I0 be the intensity at the central maximum and β be the fringe width. Then intensity at a point P which is at a distance x from the central maximum is

A pendulum with its two extreme points at (5, 12) and (12, 5) is oscillating about the origin at constant angular velocity of 180∘/sec. Find the period of pendulum (Approximate value)

A person can spin a grindstone of radius 0.32 m by placing his hand on its edge through a part of revolution. If the force of 200 N is applied perpendicular to the grindstone on its outer surface, the work done by the force through a rotation of 1 rad is

ABCD is a square of unit side. It is folded along the diagonal AC, so that the plane ABC is perpendicular to the plane ACD. The shortest distance between the lines AB and CD is

An alternating voltage V = 200 sin 100t, where V is in volt and t seconds, is connected to a series combination of 1μ farad capacitor and 10K Ω resistor through an AC ammeter. The reading of the ammeter will be

In the figure, the blocks A,B, and C of mass m each have acceleration a1,a2, and a3 respectively. F1 and F2 are external forces of magnitude 2mg and mg respectively. Thena1=a2=a3a1&gt;a3&gt;a2a1=a2,a2&gt;a3a1&gt;a2,a2=a3

In the experiment on photoelectric effect, the graph between Emax and v is found to be straight line as shown in figure. The threshold frequency and Planck's constant according to this graph are

A body starts from the origin and moves along the X-axis such that the velocity at any instant is given by (4t3−2t), where t is in sec and velocity in m/s. What is the acceleration of the particle, when it is 2 m from the origin

What is the average velocity of the coin?

In the circuit shown in figure, find the current through the branch BD

A particle free to move along the x-axis has potential energy given by U(x)=k[1−exp(−x)2] for −∞≤x≤+∞, where k is a positive constant of appropriate dimensions. Then

Two masses of 4 kg and 5 kg are connected by a string passing through a frictionless pulley and are kept on a frictionless table as shown in the figure. The acceleration of 5 kg mass is

A block of mass 2 kg, placed on a long frictionless horizontal table, is pulled horizontally by a constant force F. It is found to move 10 m in the first 2 s. Find the magnitude of the force F.

Three rods of the same dimension have thermal conductivities 3K, 2K and K. They are arranged as shown in fig. Given below, with their ends at 100o C, 50o C and 20o C. The temperature of their junction is

A ball is released from the top of a tower of height h. It takes time T to reach the ground. What is the position of the ball (from the ground after time T/3)?

Write the relation for the speed of electromagnetic waves and the amplitudes of electric and magnetic fields.

An inductor of reactance 60 Ω, capacitor of reactance 30 Ω and resistor of resistance 40 Ω are connected in series across a source of emf V=100 sin628t. Find power loss in the circuit.

A particle is suspended by thread of length l from a fixed point. If it is launched from the bottom with a horizontal speed of v=√5gl, then tension in the thread when the particle is at the topmost point

For configuration of media of permittivity ε0,ε,ε0 between parallel plates each of area A as shown in the figure; the equivalent capacitance is

The friction coefficient between a road and the tyre of a vehicle is 43 . Find the maximum incline the road may have so that once hard brakes are applied and the wheel starts skidding, the vehicle going down at a speed of 36 km/hr is stopped within 5 m.

Sir/Ma'am, What is the exact difference between energy and work?

A body dropped from a height H reaches the ground with a speed of 1.2 √gH.Calculate the work doneby air-friction.

n charged drops, each of radius r and charge q, coalesce to form a big drop of radius R and charge Q. If V is the electric potential and E is the electric field at the surface of a drop, then

The velocity of a body depends on time according to equation V=20 + 0.1 t2. the body is undergoing

The equation of a simple harmonic progressive wave is given by y = 8sin (0.628x – 12.56t) where x and y are in cm and t is in second. Find the phase difference in degrees between two particles at a distance of 2.0cm apart at any instant.

The ends of a metal rod are kept at temperatures θ1 and θ2 with θ2 &gt; θ1. The rate of flow of heat along the rod is directly proportional to.

According to Rutherford's model, what will be the kinetic energy of an electron of mass me at a distance r from the center of a Li++ ion? (The Lithium nucleus has three protons.)

The peak value of an alternating e.m.f. E is given by E=E0cos ωt is 10 volts and its frequency is 50 Hz. At time t=1600sec, the instantaneous e.m.f. is

If a particle of mass m is moving in a horizontal circle of radius r with a centripetal force (−kr2), the total energy is

Boyle's law holds for an ideal gas during

Hairs of shaving brush cling together when it is removed from water due to

A uniform solid sphere of mass M and radius a is surrounded symmetrically by a uniform thin spherical shell of equal mass and radius 2 a. the ratio of gravitational field at a distance 32 a froth the centre to 52 a from the centre is..

Water rises upto 10 cm height in a long capillary tube. If this tube is immersed in water so that the height above the water surface is only 8 cm, then

In the figure, the blocks A,B, and C of mass m each have acceleration a1,a2, and a3 respectively. F1 and F2 are external forces of magnitude 2mg and mg respectively. Thena1=a2=a3a1>a3>a2a1=a2,a2>a3a1>a2,a2=a3

The ends of a metal rod are kept at temperatures θ1 and θ2 with θ2 > θ1. The rate of flow of heat along the rod is directly proportional to.