50278 + Interview Questions in Physics

1.	Find the direction of friction on the block for the figure shown.
Answer» Find the direction of friction on the block for the figure shown.

Discussion

2.	A body is projected along a rough horizontal surface with a velocity 6 m/s. If the body comes to rest after travelling 9 m, then coefficient of sliding friction is (g=10 m/s2)
Answer» A body is projected along a rough horizontal surface with a velocity $6 m/s$ . If the body comes to rest after travelling $9 m$ , then coefficient of sliding friction is $(g = 10 {m/s}^{2})$

Discussion

3.	A three-wheeler starts from rest, accelerates uniformly with 1ms−2 on a straight road for 10 s, and then moves with uniform velocity. Plot the distance covered by the vehicle during the nth second (n = 1, 2, 3....) versus n. What do you expect this plot to be during accelerated motion: a straight line or a parabola?
Answer» A three-wheeler starts from rest, accelerates uniformly with $1 m s^{- 2}$ on a straight road for 10 s, and then moves with uniform velocity. Plot the distance covered by the vehicle during the nth second (n = 1, 2, 3....) versus n. What do you expect this plot to be during accelerated motion: a straight line or a parabola?

Discussion

4.	If the resistance of an electric component remains constant while the potential difference across two ends of the component decreases to half of its former value, what change will occur in the current through it?
Answer» If the resistance of an electric component remains constant while the potential difference across two ends of the component decreases to half of its former value, what change will occur in the current through it?

Discussion

5.	A boy whirls a stone in a horizontal circle at a height of 62.5 m above ground level and radius of circle being 3 m. Somehow, the string breaks and stone flies off horizontally and strikes the ground after travelling horizontal distance of 5 m. Find the magnitude of centripetal acceleration of stone while being in circular motion. Assume stone to be in uniform circular motion.
Answer» A boy whirls a stone in a horizontal circle at a height of $62.5 m$ above ground level and radius of circle being $3 m$ . Somehow, the string breaks and stone flies off horizontally and strikes the ground after travelling horizontal distance of $5 m$ . Find the magnitude of centripetal acceleration of stone while being in circular motion. Assume stone to be in uniform circular motion.

Discussion

6.	Wedge is fixed on a horizontal surface. Triangular block A of mass M is pulled upward by applying a constant force F parallel to the incline of the wedge as shown in the figure and there is no friction between the wedge and the block A, while coefficient of friction between A and block B of mass m is μ. If there is no relative motion between A and B, then frictional force developed between A and B is
Answer» Wedge is fixed on a horizontal surface. Triangular block A of mass $M$ is pulled upward by applying a constant force $F$ parallel to the incline of the wedge as shown in the figure and there is no friction between the wedge and the block A, while coefficient of friction between A and block B of mass $m$ is $μ .$ If there is no relative motion between A and B, then frictional force developed between A and B is

Discussion

7.	The displacement of a particle varies with time as x=12 sin ω t−16 sin3 ω t (in cm). If its motion is S.H.M., then its maximum acceleration is
Answer» The displacement of a particle varies with time as $x = 12 s i n ω t - 16 s i n^{3} ω t$ (in cm). If its motion is S.H.M., then its maximum acceleration is

Discussion

8.	Explain why (or how): a) In a sound wave, a displacement node is a pressure antinode and vice versa, b) Bats can ascertain distances, directions, nature, and sizes of the obstacles without any “eyes”, c) A violin note and sitar note may have the same frequency, yet we can distinguish between the two notes, d) Solids can support both longitudinal and transverse waves, but only longitudinal waves can propagate in gases, and e) The shape of a pulse gets distorted during propagation in a dispersive medium.
Answer» Explain why (or how): a) In a sound wave, a displacement node is a pressure antinode and vice versa, b) Bats can ascertain distances, directions, nature, and sizes of the obstacles without any “eyes”, c) A violin note and sitar note may have the same frequency, yet we can distinguish between the two notes, d) Solids can support both longitudinal and transverse waves, but only longitudinal waves can propagate in gases, and e) The shape of a pulse gets distorted during propagation in a dispersive medium.

Discussion

9.	The centre of gravity (centre of mass) of a rod (of length L) whose linear mass density varies as the square of the distance from one end is at
Answer» The centre of gravity (centre of mass) of a rod (of length $L$ ) whose linear mass density varies as the square of the distance from one end is at

Discussion

10.	When 100 volts dc is supplied across a solenoid, a current of 1.0 amperes flows in it. When 100 volts ac is applied across the same coil, the current drops to 0.5 ampere. If the frequency of ac source is 50 Hz, then the impedance and inductance of the solenoid are
Answer» When 100 volts dc is supplied across a solenoid, a current of 1.0 amperes flows in it. When 100 volts ac is applied across the same coil, the current drops to 0.5 ampere. If the frequency of ac source is 50 Hz, then the impedance and inductance of the solenoid are

Discussion

11.	A man weighs 80 kg. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5m/s2. What would be the reading on the scale. (g=10m/s2)
Answer» A man weighs 80 kg. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of $5 m / s^{2}$ . What would be the reading on the scale. $(g = 10 m / s^{2})$

Discussion

12.	An ideal gas heat engine operates in a Carnot's cycle between 227∘C and 127∘C. It absorbs 6×104J at high temperature. The amount of heat converted into work is ....
Answer» An ideal gas heat engine operates in a Carnot's cycle between $227^{\circ} C$ and $127^{\circ} C$ . It absorbs $6 \times 10^{4}$ J at high temperature. The amount of heat converted into work is ....

Discussion

13.	A truck has an initial velocity of 50 m/s. On the application of brakes truck stops at 200 m. The acceleration of the truck will be
Answer» A truck has an initial velocity of $50 m/s$ . On the application of brakes truck stops at $200 m$ . The acceleration of the truck will be

Discussion

14.	Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is
Answer» Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is

14.

Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is

Answer»

Two rods (one semi-circular and other straight) of same material and of same cross-sectional area are joined as shown in the figure. The points A and B are maintained at different temperature. The ratio of the heat transferred through a cross-section of a semi-circular rod to the heat transferred through a cross section of the straight rod in a given time is

Discussion

15.	Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.
Answer» Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.

15.

Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.

Answer»

Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.

Discussion

16.	No other thermometer is as suitable as a platinum resistance thermometer to measure temperature in the entire range of
Answer» No other thermometer is as suitable as a platinum resistance thermometer to measure temperature in the entire range of

16.

No other thermometer is as suitable as a platinum resistance thermometer to measure temperature in the entire range of

Answer»

No other thermometer is as suitable as a platinum resistance thermometer to measure temperature in the entire range of

Discussion

17.	The phase (at a time t) of a particle in simple harmonic motion tells [AMU (Engg.) 1999]
Answer» The phase (at a time t) of a particle in simple harmonic motion tells [AMU (Engg.) 1999]

17.

The phase (at a time t) of a particle in simple harmonic motion tells [AMU (Engg.) 1999]

Answer»

The phase (at a time t) of a particle in simple harmonic motion tells

[AMU (Engg.) 1999]

Discussion

18.	Force versus displacement curve is shown in the diagram. Find the change in kinetic energy by the force at the end of 30 m.
Answer» Force versus displacement curve is shown in the diagram. Find the change in kinetic energy by the force at the end of $30 m$ .

Discussion

19.	Three identical point masses, each of mass 1 kg lie in the x-y plane at points (0,0,0), (0,0.2m) and (0.2m, 0). The net gravitational force on the mass at the origin is
Answer» Three identical point masses, each of mass 1 kg lie in the x-y plane at points (0,0,0), (0,0.2m) and (0.2m, 0). The net gravitational force on the mass at the origin is

Discussion

20.	The speed of transverse waves in a string depends on:
Answer» The speed of transverse waves in a string depends on:

Discussion

21.	Two charges q1 and q2 are placed in vacuum at a distance d and the force acting between them is F. If a medium of dielectric constant 4 is introduced around them, the force now will be
Answer» Two charges $q_{1}$ and $q_{2}$ are placed in vacuum at a distance d and the force acting between them is F. If a medium of dielectric constant 4 is introduced around them, the force now will be

Discussion

22.	A ball is dropped from a height. It takes 0.200 s to cross the last 6.00 before hiting the ground, find the height from which it was dropped. Take g=10m/s2
Answer» A ball is dropped from a height. It takes 0.200 s to cross the last 6.00 before hiting the ground, find the height from which it was dropped. Take $g = 10 m / s^{2}$

Discussion

23.	If a line segment of length “l” makes an angle θ with a line then the projection of the line segment on the line will be -
Answer» If a line segment of length “l” makes an angle $θ$ with a line then the projection of the line segment on the line will be -

Discussion

24.	A hollow sphere of radius 2 cm is attached to an 18 cm long thread to make a pendulum. Find the time period of oscillation of this pendulum. How does it differ from the time period calculated using the formula for a simple pendulum ?
Answer» A hollow sphere of radius 2 cm is attached to an 18 cm long thread to make a pendulum. Find the time period of oscillation of this pendulum. How does it differ from the time period calculated using the formula for a simple pendulum ?

Discussion

25.	What is meant by calorimeter. And what is meant by bomb calorimeter.
Answer» What is meant by calorimeter. And what is meant by bomb calorimeter.

Discussion

26.	A 100 W light bulb is placed at the centre of a spherical chamber of radius 20 cm. Assume that 60% of the energy supplied to the bulb is converted into light and that the surface of the chamber is perfectly absorbing. Find the pressure exerted by the light on the surface of the chamber.
Answer» A 100 W light bulb is placed at the centre of a spherical chamber of radius 20 cm. Assume that 60 $%$ of the energy supplied to the bulb is converted into light and that the surface of the chamber is perfectly absorbing. Find the pressure exerted by the light on the surface of the chamber.

Discussion

27.	Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates. Most of the energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10 kg of water and 0.2 g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decreases by 5∘C. Specific heat capacity of water =4200 J kg−1 ∘C−1 and latent heat of vaporization of water =2.27×106 J kg−1
Answer» Indian style of cooling drinking water is to keep it in a pitcher having porous walls. Water comes to the outer surface very slowly and evaporates. Most of the energy needed for evaporation is taken from the water itself and the water is cooled down. Assume that a pitcher contains 10 kg of water and 0.2 g of water comes out per second. Assuming no backward heat transfer from the atmosphere to the water, calculate the time in which the temperature decreases by $5^{\circ} C$ . Specific heat capacity of water $= 4200 J k g^{- 1}$ $^{\circ} C^{- 1}$ and latent heat of vaporization of water $= 2.27 \times 10^{6} J k g^{- 1}$

Discussion

28.	A ball of mass m = 1 kg, rolling without slipping, strikes a smooth vertical wall and comes back. Before the impact the velocity of the ball is v1 = 10 cm/s and just after the impact v1=8 cm/s. Find the loss in energy of ball during the impact.
Answer» A ball of mass m = 1 kg, rolling without slipping, strikes a smooth vertical wall and comes back. Before the impact the velocity of the ball is $v_{1}$ = 10 cm/s and just after the impact $v_{1}$ =8 cm/s. Find the loss in energy of ball during the impact.

Discussion

29.	Starting out on a trip to the mountains, you inflate the tires on your automobile to a recommended pressure of 3.9×105 Pa on a day when the temperature is −13.0∘ C. You drive to the beach, where the temperature is 36.0∘ C. Assume that the volume of the tire has increased by 3%. What is the final pressure of air in the tires?
Answer» Starting out on a trip to the mountains, you inflate the tires on your automobile to a recommended pressure of $3.9 \times 10^{5} Pa$ on a day when the temperature is $- {13.0}^{\circ} C$ . You drive to the beach, where the temperature is ${36.0}^{\circ} C$ . Assume that the volume of the tire has increased by $3 %$ . What is the final pressure of air in the tires?

Discussion

30.	A river is flowing from west to east at a speed of 5 metres per minute. A man on the south bank of the river, capable of swimming at 10 metres per minute in still water, wants to swim across the river in the shortest time. He should swim in a direction
Answer» A river is flowing from west to east at a speed of 5 metres per minute. A man on the south bank of the river, capable of swimming at 10 metres per minute in still water, wants to swim across the river in the shortest time. He should swim in a direction

Discussion

31.	The room temperature is 25∘C.A body cools from 60∘C to 50∘C in 10 minutes. Assuming Newton’s Law of cooling to hold good, the temperature of the body at the end of next 10 minutes will be
Answer» The room temperature is $25^{\circ} C$ .A body cools from $60^{\circ} C t o 50^{\circ} C$ in 10 minutes. Assuming Newton’s Law of cooling to hold good, the temperature of the body at the end of next 10 minutes will be

Discussion

32.	In the arrangement shown in the fig the cylinder is insulating one. Both sides same diatomic gas is trapped by two insulting massless pistons with the help of an ideal spring. The natural length of the spring is equal to the length of the cylinder. Initial state of the gases are as shown in the figure. Now the gases are heated slowly, such that their temperature becomes three times to their initial temperature. The total heat given to the system is
Answer» In the arrangement shown in the fig the cylinder is insulating one. Both sides same diatomic gas is trapped by two insulting massless pistons with the help of an ideal spring. The natural length of the spring is equal to the length of the cylinder. Initial state of the gases are as shown in the figure. Now the gases are heated slowly, such that their temperature becomes three times to their initial temperature. The total heat given to the system is

32.

In the arrangement shown in the fig the cylinder is insulating one. Both sides same diatomic gas is trapped by two insulting massless pistons with the help of an ideal spring. The natural length of the spring is equal to the length of the cylinder. Initial state of the gases are as shown in the figure. Now the gases are heated slowly, such that their temperature becomes three times to their initial temperature. The total heat given to the system is

Answer»

In the arrangement shown in the fig the cylinder is insulating one. Both sides same diatomic gas is trapped by two insulting massless pistons with the help of an ideal spring. The natural length of the spring is equal to the length of the cylinder. Initial state of the gases are as shown in the figure.

Now the gases are heated slowly, such that their temperature becomes three times to their initial temperature. The total heat given to the system is

Discussion

33.	In a given circuit, switch S was closed for a long time and is opened in an instant. Charge on capacitor after time t=π1200sec after opening the switch is
Answer» In a given circuit, switch S was closed for a long time and is opened in an instant. Charge on capacitor after time $t = \frac{π}{1200} s e c$ after opening the switch is

Discussion

34.	For the arrangement of mirrors as shown in the figure, a light ray is found to retrace its path when the angle of incidence on the plane mirror is 30∘. Find the distance OP, if focal length of concave mirror is 25 cm.
Answer» For the arrangement of mirrors as shown in the figure, a light ray is found to retrace its path when the angle of incidence on the plane mirror is $30^{\circ}$ . Find the distance $O P$ , if focal length of concave mirror is $25 cm$ .

Discussion

35.	A rod of length l and mass m is bent in shape of a ring. The moment of inertia of the ring about any of its diameter is:
Answer» A rod of length $l$ and mass $m$ is bent in shape of a ring. The moment of inertia of the ring about any of its diameter is:

Discussion

36.	A rod of length 4 m is placed along positive x−axis, with one of its end at origin. If linear density of the rod varies as λ=4+x, then the position of the centre of gravity of the rod is
Answer» A rod of length $4 m$ is placed along positive $x -$ axis, with one of its end at origin. If linear density of the rod varies as $λ = 4 + x$ , then the position of the centre of gravity of the rod is

Discussion

37.	In the figure given below, the current supplied by the battery is (Assuming that the resistance of each diode is zero in forward bias and infinity in reverse bias)
Answer» In the figure given below, the current supplied by the battery is (Assuming that the resistance of each diode is zero in forward bias and infinity in reverse bias)

Discussion

38.	A block of mass m=15 kg is attached to a spring of stiffness K=100 N/m. The block descends a plane inclined at an angle α=30∘ with horizontal. Assuming there is no friction, determine the acceleration of the block when the spring has stretched by a length x=0.05 m.(Acceleration due to gravity is 10 m/s2)
Answer» A block of mass $m = 15 kg$ is attached to a spring of stiffness $K = 100 N/m$ . The block descends a plane inclined at an angle $α = 30^{\circ}$ with horizontal. Assuming there is no friction, determine the acceleration of the block when the spring has stretched by a length $x = 0.05 m$ .(Acceleration due to gravity is $10 {m/s}^{2}$ )

Discussion

39.	In the figure shown a point object O is placed in air on the principal axis. The radius of curvature of the spherical surface is 60cm. If is the final image formed after all the refractions and reflections.
Answer» In the figure shown a point object O is placed in air on the principal axis. The radius of curvature of the spherical surface is 60cm. $I_{f}$ is the final image formed after all the refractions and reflections.

39.

In the figure shown a point object O is placed in air on the principal axis. The radius of curvature of the spherical surface is 60cm. If is the final image formed after all the refractions and reflections.

Answer»

In the figure shown a point object O is placed in air on the principal axis. The radius of curvature of the spherical surface is 60cm. $I_{f}$ is the final image formed after all the refractions and reflections.

Discussion

40.	The work function of a metal is
Answer» The work function of a metal is

Discussion

41.	In the secondary circuit of a potentiometer a cell of internal resistance 1.5Ω gives balancing length of 52 cm. To get a balancing length of 40 cm, how much resistance is to be connected across the cell?
Answer» In the secondary circuit of a potentiometer a cell of internal resistance 1.5 $Ω$ gives balancing length of 52 cm. To get a balancing length of 40 cm, how much resistance is to be connected across the cell?

Discussion

42.	If a rubber ball is taken at the depth of 200 m in a pool its volume decreases by 0.2%. If the density of the water is 103kg/m3 and g=10m/s2, then the volume elasticity in N/m2 will be:
Answer» If a rubber ball is taken at the depth of 200 m in a pool its volume decreases by $0.2 %$ . If the density of the water is $10^{3} k g / m^{3}$ and $g = 10 m / s^{2}$ , then the volume elasticity in $N / m^{2}$ will be:

Discussion

43.	An isosceles triangle is formed with a thin rod of length l1 and coefficient of linear expansion α1, as the base and two thin rods each of length l2 and coefficient of linear expansion α2 as the two sides. The distance between the apex and the midpoint of the base remain unchanged as the temprature is varied. If The ratio ll:l2 is equal to n√α2α1, then the value of n is (answer upto two decimal places)
Answer» An isosceles triangle is formed with a thin rod of length $l_{1}$ and coefficient of linear expansion $α_{1}$ , as the base and two thin rods each of length $l_{2}$ and coefficient of linear expansion $α_{2}$ as the two sides. The distance between the apex and the midpoint of the base remain unchanged as the temprature is varied. If The ratio $l_{l} : l_{2}$ is equal to $n \sqrt{\frac{α_{2}}{α_{1}}}$ , then the value of $n$ is (answer upto two decimal places)

Discussion

44.	Determine the intensity after polarizer C. Axis of orientations are given. Initial intensity is Io units.
Answer» Determine the intensity after polarizer C. Axis of orientations are given. Initial intensity is $I_{o}$ units.

Discussion

45.	A non-isotropic solid metal cube has coefficient of linear expansion as 5×10−5/∘C along the x-axis and 5×10−6/∘C along y-axis and z-axis. If the coefficient of volumetric expansion of the solid is C×10−6/∘C then the value of C is
Answer» A non-isotropic solid metal cube has coefficient of linear expansion as $5 \times 10^{- 5} /^{\circ} C$ along the x-axis and $5 \times 10^{- 6} /^{\circ} C$ along y-axis and z-axis. If the coefficient of volumetric expansion of the solid is $C \times 10^{- 6} /^{\circ} C$ then the value of $C$ is

Discussion

46.	In the figure shown ABCDEFA was a square loop of side l , but is folded in two equal parts so that half of it lies in XZ plane and the other half lies in the YZ plane. The origin O is centre of the frame also. The loop carries current. The magnetic field at the centre is :
Answer» In the figure shown ABCDEFA was a square loop of side l , but is folded in two equal parts so that half of it lies in XZ plane and the other half lies in the YZ plane. The origin O is centre of the frame also. The loop carries current. The magnetic field at the centre is :

Discussion

47.	A vertical U-tube of uniform cross-section contains water in both the arms. A 12 cm glycerine column (Relative density =1.2) is added to one of the limbs. The level difference between the two surfaces of both the limbs will be
Answer» A vertical U-tube of uniform cross-section contains water in both the arms. A $12 cm$ glycerine column (Relative density $= 1.2$ ) is added to one of the limbs. The level difference between the two surfaces of both the limbs will be

Discussion

48.	A parallel-plate capacitor is constructed using three different dielectric materials as shown in the figure. What is the capacitance across P and Q?
Answer» A parallel-plate capacitor is constructed using three different dielectric materials as shown in the figure. What is the capacitance across P and Q?

Discussion

49.	If the charges are in equilibrium, what is the net force on the 1C charge on the right top corner if the side of the square is 1m and if they are in vacuum?
Answer» If the charges are in equilibrium, what is the net force on the 1C charge on the right top corner if the side of the square is 1m and if they are in vacuum?

49.

If the charges are in equilibrium, what is the net force on the 1C charge on the right top corner if the side of the square is 1m and if they are in vacuum?

Answer»

If the charges are in equilibrium, what is the net force on the 1C charge on the right top corner if the side of the square is 1m and if they are in vacuum?

Discussion

50.	A stone is dropped into a lake by a man from a tower of height 500 m. The sound of the splash will be heard by the man after [velocity of sound in air =340 ms−1]
Answer» A stone is dropped into a lake by a man from a tower of height $500 m$ . The sound of the splash will be heard by the man after [velocity of sound in air $= 340 {ms}^{- 1}$ ]

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Find the direction of friction on the block for the figure shown.

A body is projected along a rough horizontal surface with a velocity 6 m/s. If the body comes to rest after travelling 9 m, then coefficient of sliding friction is (g=10 m/s2)

If the resistance of an electric component remains constant while the potential difference across two ends of the component decreases to half of its former value, what change will occur in the current through it?

The displacement of a particle varies with time as x=12 sin ω t−16 sin3 ω t (in cm). If its motion is S.H.M., then its maximum acceleration is

The centre of gravity (centre of mass) of a rod (of length L) whose linear mass density varies as the square of the distance from one end is at

When 100 volts dc is supplied across a solenoid, a current of 1.0 amperes flows in it. When 100 volts ac is applied across the same coil, the current drops to 0.5 ampere. If the frequency of ac source is 50 Hz, then the impedance and inductance of the solenoid are

A man weighs 80 kg. He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5m/s2. What would be the reading on the scale. (g=10m/s2)

An ideal gas heat engine operates in a Carnot's cycle between 227∘C and 127∘C. It absorbs 6×104J at high temperature. The amount of heat converted into work is ....

A truck has an initial velocity of 50 m/s. On the application of brakes truck stops at 200 m. The acceleration of the truck will be

Calculate the work done by an ideal gas as it is taken through the process (1 - 2 - 3) as shown in the graph below.

No other thermometer is as suitable as a platinum resistance thermometer to measure temperature in the entire range of

The phase (at a time t) of a particle in simple harmonic motion tells [AMU (Engg.) 1999]

Force versus displacement curve is shown in the diagram. Find the change in kinetic energy by the force at the end of 30 m.

Three identical point masses, each of mass 1 kg lie in the x-y plane at points (0,0,0), (0,0.2m) and (0.2m, 0). The net gravitational force on the mass at the origin is

The speed of transverse waves in a string depends on:

Two charges q1 and q2 are placed in vacuum at a distance d and the force acting between them is F. If a medium of dielectric constant 4 is introduced around them, the force now will be

A ball is dropped from a height. It takes 0.200 s to cross the last 6.00 before hiting the ground, find the height from which it was dropped. Take g=10m/s2

If a line segment of length “l” makes an angle θ with a line then the projection of the line segment on the line will be -

A hollow sphere of radius 2 cm is attached to an 18 cm long thread to make a pendulum. Find the time period of oscillation of this pendulum. How does it differ from the time period calculated using the formula for a simple pendulum ?

What is meant by calorimeter. And what is meant by bomb calorimeter.

A 100 W light bulb is placed at the centre of a spherical chamber of radius 20 cm. Assume that 60% of the energy supplied to the bulb is converted into light and that the surface of the chamber is perfectly absorbing. Find the pressure exerted by the light on the surface of the chamber.

A ball of mass m = 1 kg, rolling without slipping, strikes a smooth vertical wall and comes back. Before the impact the velocity of the ball is v1 = 10 cm/s and just after the impact v1=8 cm/s. Find the loss in energy of ball during the impact.

A river is flowing from west to east at a speed of 5 metres per minute. A man on the south bank of the river, capable of swimming at 10 metres per minute in still water, wants to swim across the river in the shortest time. He should swim in a direction

The room temperature is 25∘C.A body cools from 60∘C to 50∘C in 10 minutes. Assuming Newton’s Law of cooling to hold good, the temperature of the body at the end of next 10 minutes will be

In a given circuit, switch S was closed for a long time and is opened in an instant. Charge on capacitor after time t=π1200sec after opening the switch is

For the arrangement of mirrors as shown in the figure, a light ray is found to retrace its path when the angle of incidence on the plane mirror is 30∘. Find the distance OP, if focal length of concave mirror is 25 cm.

A rod of length l and mass m is bent in shape of a ring. The moment of inertia of the ring about any of its diameter is:

A rod of length 4 m is placed along positive x−axis, with one of its end at origin. If linear density of the rod varies as λ=4+x, then the position of the centre of gravity of the rod is

In the figure given below, the current supplied by the battery is (Assuming that the resistance of each diode is zero in forward bias and infinity in reverse bias)

In the figure shown a point object O is placed in air on the principal axis. The radius of curvature of the spherical surface is 60cm. If is the final image formed after all the refractions and reflections.

The work function of a metal is

In the secondary circuit of a potentiometer a cell of internal resistance 1.5Ω gives balancing length of 52 cm. To get a balancing length of 40 cm, how much resistance is to be connected across the cell?

If a rubber ball is taken at the depth of 200 m in a pool its volume decreases by 0.2%. If the density of the water is 103kg/m3 and g=10m/s2, then the volume elasticity in N/m2 will be:

Determine the intensity after polarizer C. Axis of orientations are given. Initial intensity is Io units.

A non-isotropic solid metal cube has coefficient of linear expansion as 5×10−5/∘C along the x-axis and 5×10−6/∘C along y-axis and z-axis. If the coefficient of volumetric expansion of the solid is C×10−6/∘C then the value of C is

In the figure shown ABCDEFA was a square loop of side l , but is folded in two equal parts so that half of it lies in XZ plane and the other half lies in the YZ plane. The origin O is centre of the frame also. The loop carries current. The magnetic field at the centre is :

A vertical U-tube of uniform cross-section contains water in both the arms. A 12 cm glycerine column (Relative density =1.2) is added to one of the limbs. The level difference between the two surfaces of both the limbs will be

A parallel-plate capacitor is constructed using three different dielectric materials as shown in the figure. What is the capacitance across P and Q?

If the charges are in equilibrium, what is the net force on the 1C charge on the right top corner if the side of the square is 1m and if they are in vacuum?

A stone is dropped into a lake by a man from a tower of height 500 m. The sound of the splash will be heard by the man after [velocity of sound in air =340 ms−1]