50278 + Interview Questions in Physics

1.	The mass of hydrogen molecule is 3.32×10−27 kg. If 1023 hydrogen molecules strike per second at 2 cm2 area of rigid wall of a close container normally and rebound back with the speed of 1000 m/s, then the pressure exerted on the wall (according to kinetic theory of gas) is
Answer» The mass of hydrogen molecule is $3.32 \times 10^{- 27} kg$ . If $10^{23}$ hydrogen molecules strike per second at $2 {cm}^{2}$ area of rigid wall of a close container normally and rebound back with the speed of $1000 m/s$ , then the pressure exerted on the wall (according to kinetic theory of gas) is

Discussion

2.	Mass M is divided into two parts x M and (1 - x)M. For a given separation, the value of x for which the gravitational attraction between the two pieces becomes maximum is
Answer» Mass M is divided into two parts x M and (1 - x)M. For a given separation, the value of x for which the gravitational attraction between the two pieces becomes maximum is

Discussion

3.	Two masses m and 2m are joined to each other by means of a frictionless pulley as shown below. When the mass 2m is released, the mass m will ascend with an acceleration of
Answer» Two masses m and 2m are joined to each other by means of a frictionless pulley as shown below. When the mass 2m is released, the mass m will ascend with an acceleration of

Discussion

4.	The amplitude of vibration of a particle is given by am=(a0)(aω2−bω+c) where a0,a,b and c are positive. The condition for a single resonant frequency is
Answer» The amplitude of vibration of a particle is given by $a_{m} = \frac{(a_{0})}{(a ω^{2} - b ω + c)}$ where $a_{0}, a, b$ and c are positive. The condition for a single resonant frequency is

4.

The amplitude of vibration of a particle is given by am=(a0)(aω2−bω+c) where a0,a,b and c are positive. The condition for a single resonant frequency is

Answer»

The amplitude of vibration of a particle is given by $a_{m} = \frac{(a_{0})}{(a ω^{2} - b ω + c)}$ where $a_{0}, a, b$ and c are positive. The condition for a single resonant frequency is

Discussion

5.	A ball falling freely from a height of 4.9 m, hits a horizontal surface. If e=34, then the ball will hit the surface, second time after
Answer» A ball falling freely from a height of $4.9 m$ , hits a horizontal surface. If $e = \frac{3}{4}$ , then the ball will hit the surface, second time after

Discussion

6.	Mountain roads rarely go straight up the slope but wind up gradually. Why?
Answer» Mountain roads rarely go straight up the slope but wind up gradually. Why?

Discussion

7.	A mon of mass m moves on a plank of mass M with a constant velocity u eith respect to the plank , as shown in figure. If the plank rests on a smooth horizontal surface, then determine the velocity of the plank.
Answer» A mon of mass m moves on a plank of mass M with a constant velocity u eith respect to the plank , as shown in figure. If the plank rests on a smooth horizontal surface, then determine the velocity of the plank.

Discussion

8.	A wire has a length of 2.0 m and a resistance of 5.0 Ω Find the electric field existing inside the wire if it carries a current of 10 A.
Answer» A wire has a length of 2.0 m and a resistance of 5.0 $Ω$ Find the electric field existing inside the wire if it carries a current of 10 A.

8.

A wire has a length of 2.0 m and a resistance of 5.0 Ω Find the electric field existing inside the wire if it carries a current of 10 A.

Answer»

A wire has a length of 2.0 m and a resistance of 5.0 $Ω$ Find the electric field existing inside the wire if it carries a current of 10 A.

Discussion

9.	Viewing glass of a fish aquarium is of plane convex lens type with radius of curvature R=30 cm. and refractive index 1.5, If the fish is at 20 cm from glass in water of refractive index 1.2, distance of fish for observer from glass in cm will be (neglect thickness of glass) .
Answer» Viewing glass of a fish aquarium is of plane convex lens type with radius of curvature $R = 30 c m$ . and refractive index 1.5, If the fish is at 20 cm from glass in water of refractive index 1.2, distance of fish for observer from glass in cm will be (neglect thickness of glass) .

Discussion

10.	Spherical sound waves are emitted uniformly in all directions from a point source. The variation in sound level SL as a function of distance ‘r’ from the source can be written as Where a and b are positive constants.
Answer» Spherical sound waves are emitted uniformly in all directions from a point source. The variation in sound level SL as a function of distance ‘r’ from the source can be written as Where a and b are positive constants.

Discussion

11.	(a) Draw the plot of binding energy per nucleon (BE/A) as a function of mass number. Write two important conclusions that can be drawn regarding the nature of nuclear source. (b) Use this graph to explain the release of energy in both the processes of nuclear fusion and fission. (c) Write the basic nuclear process of neutron undergoing β -decay. Why is the detection of neutrinos found very difficult?
Answer» (a) Draw the plot of binding energy per nucleon (BE/A) as a function of mass number. Write two important conclusions that can be drawn regarding the nature of nuclear source. (b) Use this graph to explain the release of energy in both the processes of nuclear fusion and fission. (c) Write the basic nuclear process of neutron undergoing $β$ -decay. Why is the detection of neutrinos found very difficult?

Discussion

12.	Light is incident from glass (μ=1.5) to air. Sketch the variation of the angle of deviation δ with the angle of incident i for 0<i<90∘.
Answer» Light is incident from glass $(μ = 1.5)$ to air. Sketch the variation of the angle of deviation $δ$ with the angle of incident i for $0 < i < 90^{\circ}$ .

Discussion

13.	A metre scale made of steel reads accurately at 20∘C. In a sensitive experiment, distances accurate up to 0.055 mm in 1 m are required. Find the range of temperature in which the experiment can be performed with this metre scale. Coefficient of linear expansion of steel =11×10−6 ∘C−1
Answer» A metre scale made of steel reads accurately at $20^{\circ} C$ . In a sensitive experiment, distances accurate up to 0.055 mm in 1 m are required. Find the range of temperature in which the experiment can be performed with this metre scale. Coefficient of linear expansion of steel $= 11 \times 10^{- 6}^{\circ} C^{- 1}$

Discussion

14.	A cricket mat of mass 50 kg is rolled loosely in the form of a cylinder of radius 2 m. Now again it is rolled tightly so that the radius becomes (34)th of original value, then the ratio of moment of inertia of mat in the two cases is
Answer» A cricket mat of mass $50 kg$ is rolled loosely in the form of a cylinder of radius $2 m$ . Now again it is rolled tightly so that the radius becomes ${(\frac{3}{4})}^{t h}$ of original value, then the ratio of moment of inertia of mat in the two cases is

Discussion

15.	Three rods of material x and two rods of material y are connected as shown in the figure here. All the rods are identical (each 1 cm long and of cross-sectional area 100cm2). At the junctions A and C, there are two sources of heat 25W and 100 W, and at B and at D there are two sinks maintained at 30∘C and 10∘C, respectively. Calculate the temperatures of the points A and C in the steady state. The thermal conductivity of x is 200 Js−1m−1K−1 and that of y is 400 Js−1m−1K−1.
Answer» Three rods of material x and two rods of material y are connected as shown in the figure here. All the rods are identical (each 1 cm long and of cross-sectional area $100 c m^{2}$ ). At the junctions A and C, there are two sources of heat 25W and 100 W, and at B and at D there are two sinks maintained at $30^{\circ} C$ and $10^{\circ} C$ , respectively. Calculate the temperatures of the points A and C in the steady state. The thermal conductivity of x is $200 J s^{- 1} m^{- 1} K^{- 1}$ and that of y is $400 J s^{- 1} m^{- 1} K^{- 1}$ .

Discussion

16.	A block of mass 5 kg is on a rough horizontal surface and is at rest. Now a force of 24 N is imparted to it with negligible impulse. If the coefficient of kinetic friction is 0.4 and g=9.8 m/s2, then the acceleration of the block is
Answer» A block of mass 5 kg is on a rough horizontal surface and is at rest. Now a force of 24 N is imparted to it with negligible impulse. If the coefficient of kinetic friction is 0.4 and g=9.8 $m / s^{2}$ , then the acceleration of the block is

Discussion

17.	Coefficient of kinetic friction between 3 kg and 2 kg block is 0.25. The horizontal table surface is smooth. Find the acceleration of block of mass 10 kg is .(in ms−2)
Answer» Coefficient of kinetic friction between 3 kg and 2 kg block is 0.25. The horizontal table surface is smooth. Find the acceleration of block of mass 10 kg is .(in $m s^{- 2}$ )

Discussion

18.	The ratio of the slopes of p – V graphs of adiabatic and isothermal is
Answer» The ratio of the slopes of p – V graphs of adiabatic and isothermal is

Discussion

19.	A block is kept on the floor of an elevator at rest. The elevator starts descending with an acceleration of 12m/s2. Find the displacement of the block during the first 0.2 s after the start. Take g = 10m/s2.
Answer» A block is kept on the floor of an elevator at rest. The elevator starts descending with an acceleration of $12 m / s^{2}$ . Find the displacement of the block during the first 0.2 s after the start. Take g = 10 $m / s^{2}$ .

Discussion

20.	A cricket ball of mass 150 gm is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back with a velocity of 20 m/s. The force of blow acts for 0.01s on the ball. The average force exerted by the bat on the ball is
Answer» A cricket ball of mass 150 gm is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back with a velocity of 20 m/s. The force of blow acts for 0.01s on the ball. The average force exerted by the bat on the ball is

Discussion

21.	A weightless thread can support tension upto 30 N. A stone of mass 0.5 kg is tied to it and is revolved in a circular path of radius 2 m in a vertical plane. If g= 10m/s2 , then the maximum angular velocity of the stone will be
Answer» A weightless thread can support tension upto 30 N. A stone of mass 0.5 kg is tied to it and is revolved in a circular path of radius 2 m in a vertical plane. If g= 10m/ $s^{2}$ , then the maximum angular velocity of the stone will be

Discussion

22.	Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury , soap solution and water are 0.46Nm−1,0.03Nm−1 and 0.076Nm−1 respectively.
Answer» Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury , soap solution and water are $0.46 N m^{- 1}, 0.03 N m^{- 1}$ and $0.076 N m^{- 1}$ respectively.

22.

Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury , soap solution and water are 0.46Nm−1,0.03Nm−1 and 0.076Nm−1 respectively.

Answer»

Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury , soap solution and water are $0.46 N m^{- 1}, 0.03 N m^{- 1}$ and $0.076 N m^{- 1}$ respectively.

Discussion

23.	In the following arrangement the system is initially at rest. The 5 Kg block is now released. Assuming the pulleys and strings to be massless and smooth, the acceleration of block ‘C’ is: (take g=9.8m/s2)
Answer» In the following arrangement the system is initially at rest. The 5 Kg block is now released. Assuming the pulleys and strings to be massless and smooth, the acceleration of block ‘C’ is: (take $g = 9.8 m / s^{2})$

Discussion

24.	A rotating mirror with uniform angular speed ω is placed at the centre (C) of the sphere of radius (R) as shown in the figure. Incident light falls on the mirror. The linear speed (v) of the light spot on the sphere is
Answer» A rotating mirror with uniform angular speed $ω$ is placed at the centre $(C)$ of the sphere of radius $(R)$ as shown in the figure. Incident light falls on the mirror. The linear speed $(v)$ of the light spot on the sphere is

Discussion

25.	A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown, Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed ω.
Answer» A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown, Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed $ω$ .

25.

A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown, Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed ω.

Answer»

A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown, Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed $ω$ .

Discussion

26.	There are two identical small holes on the opposite sides of a tank containing a liquid. The tank is open at the top. The difference in height between the two holes is h. As the liquid comes out of the two holes, calculate the total force experienced by the tank.
Answer» There are two identical small holes on the opposite sides of a tank containing a liquid. The tank is open at the top. The difference in height between the two holes is $h$ . As the liquid comes out of the two holes, calculate the total force experienced by the tank.

Discussion

27.	Unpolarized light of intensity I passes through an ideal polarizer A. Another identical polarizer B is placed behind A. The intensity of light beyond B is found to be I2. Now another identical polarizer C is placed between A and B. The intensity beyond B is now found to be I8. The angle between polarizer A and C is :
Answer» Unpolarized light of intensity I passes through an ideal polarizer A. Another identical polarizer $B$ is placed behind $A$ . The intensity of light beyond $B$ is found to be $\frac{I}{2} .$ Now another identical polarizer $C$ is placed between $A$ and $B$ . The intensity beyond $B$ is now found to be $\frac{I}{8} .$ The angle between polarizer $A$ and $C$ is :

Discussion

28.	A uniform magnetic field of 0.20×10−3 T exists in the space. Find the change in the magnetic scalar potential 'as one moves through 50 cm along the field
Answer» A uniform magnetic field of $0.20 \times 10^{- 3}$ T exists in the space. Find the change in the magnetic scalar potential 'as one moves through 50 cm along the field

Discussion

29.	Draw a labelled diagram of Van de Graaff generator. State its working principle to show how introducing a small charged sphere into a larger sphere, a large amount of charge can be transferred to the outer sphere. State the use of this machine and also point out its limitations.
Answer» Draw a labelled diagram of Van de Graaff generator. State its working principle to show how introducing a small charged sphere into a larger sphere, a large amount of charge can be transferred to the outer sphere. State the use of this machine and also point out its limitations.

Discussion

30.	When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface then
Answer» When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface then

Discussion

31.	Consider the four processes A,B,C,D shown in the graph given below List I shows process & List II gives value of index ′n′ for the equation PVn=const Match List I with list II. List IList IIA.A1.0BB21CC3.1.4DD4.∞
Answer» Consider the four processes $A, B, C, D$ shown in the graph given below List I shows process & List II gives value of index $^{'} n^{'}$ for the equation $P V^{n} = const$ Match List I with list II. $\begin{matrix} List I & List II A . & A & 1. & 0 B & B & 2 & 1 C & C & 3. & 1.4 D & D & 4. & \infty \end{matrix}$

Discussion

32.	Two waves represented by equation y1=Asin(ωt−kx+ϕ1) and y2=Asin(ωt−kx+ϕ2) are superimposed such that the amplitude of resultant wave is A. Find the phase difference between them. Given: (ϕ1>ϕ2)
Answer» Two waves represented by equation $y_{1} = A sin (ω t - k x + ϕ_{1})$ and $y_{2} = A sin (ω t - k x + ϕ_{2})$ are superimposed such that the amplitude of resultant wave is $A$ . Find the phase difference between them. Given: $(ϕ_{1} > ϕ_{2})$

Discussion

33.	Radiation of wavelength λ, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to 3λ4, the speed of the fastest emitted electron will be:
Answer» Radiation of wavelength $λ$ , is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to $\frac{3 λ}{4}$ , the speed of the fastest emitted electron will be:

Discussion

34.	Trajectory of two particles projected from origin with speeds v1 and v2 at angles θ1 and θ2 with positive x-axis respectively are as shown in the figure. Given that g=−10 m/s2(^j). Choose the correct option(s) related to diagram.
Answer» Trajectory of two particles projected from origin with speeds $v_{1}$ and $v_{2}$ at angles $θ_{1}$ and $θ_{2}$ with positive x-axis respectively are as shown in the figure. Given that $g = - 10 {m/s}^{2} (^j)$ . Choose the correct option(s) related to diagram.

Discussion

35.	The graph shows how the magnification m produced by a convex thin lens varies with image distance v. What was the focal length of the used
Answer» The graph shows how the magnification m produced by a convex thin lens varies with image distance v. What was the focal length of the used

Discussion

36.	A shell of mass '2m' fired with a speed 'u' at an angle θ to the horizontal explodes at the highest point of its motion into two fragments of mass 'm' each. If one fragment, falls vertically, the distance at which the other fragment falls from the gun is given by
Answer» A shell of mass '2m' fired with a speed 'u' at an angle $θ$ to the horizontal explodes at the highest point of its motion into two fragments of mass 'm' each. If one fragment, falls vertically, the distance at which the other fragment falls from the gun is given by

Discussion

37.	A light pointer fixed to one prong of a tuning fork touches a vertical smoked plate. The fork is set to vibration and the plate is allowed to fall freely. Eight complete waves are counted when the plate falls through 10 cm. The frequency of the tuning fork is
Answer» A light pointer fixed to one prong of a tuning fork touches a vertical smoked plate. The fork is set to vibration and the plate is allowed to fall freely. Eight complete waves are counted when the plate falls through 10 cm. The frequency of the tuning fork is

Discussion

38.	The speed of a transverse wave, travelling on a wire having a length of 100 cm and mass 10 g is 160 m/s. The area of cross-section of the wire is 2 mm2 and its Young's modulus is 32×1011 N/m2. Find the extension of the wire from its natural length.
Answer» The speed of a transverse wave, travelling on a wire having a length of $100 cm$ and mass $10 g$ is $160 m/s$ . The area of cross-section of the wire is $2 {mm}^{2}$ and its Young's modulus is $32 \times 10^{11} {N/m}^{2}$ . Find the extension of the wire from its natural length.

Discussion

39.	A capacitor of 10 μF and an inductor of 1 H are joined in series. An AC of 50 Hz is applied to this combination. What is the impedance of the combination?
Answer» A capacitor of $10 μ F$ and an inductor of $1 H$ are joined in series. An $A C$ of $50 Hz$ is applied to this combination. What is the impedance of the combination?

Discussion

40.	Two blocks are placed over a rough pulley of moment of inertia I. When the block of mass M comes down by a distance h, the angular speed of the pulley is
Answer» Two blocks are placed over a rough pulley of moment of inertia I. When the block of mass M comes down by a distance h, the angular speed of the pulley is

40.

Two blocks are placed over a rough pulley of moment of inertia I. When the block of mass M comes down by a distance h, the angular speed of the pulley is

Answer»

Two blocks are placed over a rough pulley of moment of inertia I. When the block of mass M comes down by a distance h, the angular speed of the pulley is

Discussion

41.	A uniform chain of length l and mass m overhangs a smooth table with two third part lying on the table. Find the kinetic energy of the chain as it completely slips off the table.
Answer» A uniform chain of length $l$ and mass $m$ overhangs a smooth table with two third part lying on the table. Find the kinetic energy of the chain as it completely slips off the table.

Discussion

42.	What is the output Y in the following circuit when all the three inputs A, B, C are first 0 and then 1 ?
Answer» What is the output Y in the following circuit when all the three inputs A, B, C are first $0$ and then $1$ ?

Discussion

43.	Can 2 equation having same unit must have same dimrdimens? If all terms have same dimensions,is it necessary that they have same units.
Answer» Can 2 equation having same unit must have same dimrdimens? If all terms have same dimensions,is it necessary that they have same units.

43.

Can 2 equation having same unit must have same dimrdimens? If all terms have same dimensions,is it necessary that they have same units.

Answer»

Can 2 equation having same unit must have same dimrdimens?

If all terms have same dimensions,is it necessary that they have same units.

Discussion

44.	In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across 52 cm of the potentiometer wire. If the cell is shunted by the resistance of 5 Ω, a balance is found when the cell is connected across 40 cm of the wire. Find the internal resistance of the cell.
Answer» In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across $52 c m$ of the potentiometer wire. If the cell is shunted by the resistance of $5 Ω$ , a balance is found when the cell is connected across $40 c m$ of the wire. Find the internal resistance of the cell.

Discussion

45.	A 12-volt car battery can deliver a total charge of 100 ampere-hours. Using this battery how many 100 µF capacitors can be fully charged?
Answer» A 12-volt car battery can deliver a total charge of 100 ampere-hours. Using this battery how many 100 µF capacitors can be fully charged?

Discussion

46.	One conducting U tube can slide inside another as shown in ﬁgure maintaining electrical contacts between the tubes. The magnetic ﬁeld B is perpendicular to the plane of the ﬁgure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v, where l is the width of each tube, will be
Answer» One conducting U tube can slide inside another as shown in ﬁgure maintaining electrical contacts between the tubes. The magnetic ﬁeld B is perpendicular to the plane of the ﬁgure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v, where l is the width of each tube, will be

46.

One conducting U tube can slide inside another as shown in ﬁgure maintaining electrical contacts between the tubes. The magnetic ﬁeld B is perpendicular to the plane of the ﬁgure. If each tube moves towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v, where l is the width of each tube, will be

Answer»

One conducting U tube can slide inside another as shown in ﬁgure maintaining electrical contacts between the tubes. The magnetic ﬁeld B is perpendicular to the plane of the ﬁgure. If each tube moves

towards the other at a constant speed v, then the emf induced in the circuit in terms of B, l and v, where l is the width of each tube, will be

Discussion

47.	The potential energy of a particle of mass 1 kg moving along the X-axis is given by U=4(1+cos2x) J, where x is in meters. Find the time period of small oscillation (in second).
Answer» The potential energy of a particle of mass $1 kg$ moving along the $X$ -axis is given by $U = 4 (1 + cos 2 x) J,$ where $x$ is in meters. Find the time period of small oscillation (in second).

Discussion

48.	A U tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are at the same level with 10cm of water in one arm and 12.5cm of spirit in the other as shown in figure. The relative density of the spirit is
Answer» A U tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are at the same level with 10cm of water in one arm and 12.5cm of spirit in the other as shown in figure. The relative density of the spirit is

48.

A U tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are at the same level with 10cm of water in one arm and 12.5cm of spirit in the other as shown in figure. The relative density of the spirit is

Answer»

A U tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are at the same level with 10cm of water in one arm and 12.5cm of spirit in the other as shown in figure. The relative density of the spirit is

Discussion

49.	Two long conductors separated by a distance d carry currents i1 and i2 in the same direction. They exert a force F on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to 3d. The new value of the force between them is
Answer» Two long conductors separated by a distance d carry currents $i_{1}$ and $i_{2}$ in the same direction. They exert a force F on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to 3d. The new value of the force between them is

Discussion

50.	The magnetic field due to a straight conductor of uniform cross section of radius a and carrying a steady current is represented by
Answer» The magnetic field due to a straight conductor of uniform cross section of radius a and carrying a steady current is represented by

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The mass of hydrogen molecule is 3.32×10−27 kg. If 1023 hydrogen molecules strike per second at 2 cm2 area of rigid wall of a close container normally and rebound back with the speed of 1000 m/s, then the pressure exerted on the wall (according to kinetic theory of gas) is

Mass M is divided into two parts x M and (1 - x)M. For a given separation, the value of x for which the gravitational attraction between the two pieces becomes maximum is

Two masses m and 2m are joined to each other by means of a frictionless pulley as shown below. When the mass 2m is released, the mass m will ascend with an acceleration of

The amplitude of vibration of a particle is given by am=(a0)(aω2−bω+c) where a0,a,b and c are positive. The condition for a single resonant frequency is

A ball falling freely from a height of 4.9 m, hits a horizontal surface. If e=34, then the ball will hit the surface, second time after

Mountain roads rarely go straight up the slope but wind up gradually. Why?

A mon of mass m moves on a plank of mass M with a constant velocity u eith respect to the plank , as shown in figure. If the plank rests on a smooth horizontal surface, then determine the velocity of the plank.

A wire has a length of 2.0 m and a resistance of 5.0 Ω Find the electric field existing inside the wire if it carries a current of 10 A.

Viewing glass of a fish aquarium is of plane convex lens type with radius of curvature R=30 cm. and refractive index 1.5, If the fish is at 20 cm from glass in water of refractive index 1.2, distance of fish for observer from glass in cm will be (neglect thickness of glass) .

Spherical sound waves are emitted uniformly in all directions from a point source. The variation in sound level SL as a function of distance ‘r’ from the source can be written as Where a and b are positive constants.

Light is incident from glass (μ=1.5) to air. Sketch the variation of the angle of deviation δ with the angle of incident i for 0&lt;i&lt;90∘.

A metre scale made of steel reads accurately at 20∘C. In a sensitive experiment, distances accurate up to 0.055 mm in 1 m are required. Find the range of temperature in which the experiment can be performed with this metre scale. Coefficient of linear expansion of steel =11×10−6 ∘C−1

A cricket mat of mass 50 kg is rolled loosely in the form of a cylinder of radius 2 m. Now again it is rolled tightly so that the radius becomes (34)th of original value, then the ratio of moment of inertia of mat in the two cases is

A block of mass 5 kg is on a rough horizontal surface and is at rest. Now a force of 24 N is imparted to it with negligible impulse. If the coefficient of kinetic friction is 0.4 and g=9.8 m/s2, then the acceleration of the block is

Coefficient of kinetic friction between 3 kg and 2 kg block is 0.25. The horizontal table surface is smooth. Find the acceleration of block of mass 10 kg is .(in ms−2)

The ratio of the slopes of p – V graphs of adiabatic and isothermal is

A block is kept on the floor of an elevator at rest. The elevator starts descending with an acceleration of 12m/s2. Find the displacement of the block during the first 0.2 s after the start. Take g = 10m/s2.

A cricket ball of mass 150 gm is moving with a velocity of 12 m/s and is hit by a bat so that the ball is turned back with a velocity of 20 m/s. The force of blow acts for 0.01s on the ball. The average force exerted by the bat on the ball is

A weightless thread can support tension upto 30 N. A stone of mass 0.5 kg is tied to it and is revolved in a circular path of radius 2 m in a vertical plane. If g= 10m/s2 , then the maximum angular velocity of the stone will be

Find the excess pressure inside (a) a drop of mercury of radius 2 mm (b) a soap bubble of radius 4 mm and (c) an air bubble of radius 4 mm formed inside a tank of water. Surface tension of mercury , soap solution and water are 0.46Nm−1,0.03Nm−1 and 0.076Nm−1 respectively.

In the following arrangement the system is initially at rest. The 5 Kg block is now released. Assuming the pulleys and strings to be massless and smooth, the acceleration of block ‘C’ is: (take g=9.8m/s2)

A rotating mirror with uniform angular speed ω is placed at the centre (C) of the sphere of radius (R) as shown in the figure. Incident light falls on the mirror. The linear speed (v) of the light spot on the sphere is

A particle of mass m is attached to M via a massless string passing through a hole O in the horizontal table as shown, Mass M is kept stationary whereas mass m is rotating in a circle of radius r with angular speed ω.

There are two identical small holes on the opposite sides of a tank containing a liquid. The tank is open at the top. The difference in height between the two holes is h. As the liquid comes out of the two holes, calculate the total force experienced by the tank.

A uniform magnetic field of 0.20×10−3 T exists in the space. Find the change in the magnetic scalar potential 'as one moves through 50 cm along the field

Draw a labelled diagram of Van de Graaff generator. State its working principle to show how introducing a small charged sphere into a larger sphere, a large amount of charge can be transferred to the outer sphere. State the use of this machine and also point out its limitations.

When yellow light is incident on a surface, no electrons are emitted while green light can emit. If red light is incident on the surface then

Consider the four processes A,B,C,D shown in the graph given below List I shows process &amp; List II gives value of index ′n′ for the equation PVn=const Match List I with list II. List IList IIA.A1.0BB21CC3.1.4DD4.∞

Two waves represented by equation y1=Asin(ωt−kx+ϕ1) and y2=Asin(ωt−kx+ϕ2) are superimposed such that the amplitude of resultant wave is A. Find the phase difference between them. Given: (ϕ1&gt;ϕ2)

Radiation of wavelength λ, is incident on a photocell. The fastest emitted electron has speed v. If the wavelength is changed to 3λ4, the speed of the fastest emitted electron will be:

Trajectory of two particles projected from origin with speeds v1 and v2 at angles θ1 and θ2 with positive x-axis respectively are as shown in the figure. Given that g=−10 m/s2(^j). Choose the correct option(s) related to diagram.

The graph shows how the magnification m produced by a convex thin lens varies with image distance v. What was the focal length of the used

A shell of mass '2m' fired with a speed 'u' at an angle θ to the horizontal explodes at the highest point of its motion into two fragments of mass 'm' each. If one fragment, falls vertically, the distance at which the other fragment falls from the gun is given by

A light pointer fixed to one prong of a tuning fork touches a vertical smoked plate. The fork is set to vibration and the plate is allowed to fall freely. Eight complete waves are counted when the plate falls through 10 cm. The frequency of the tuning fork is

The speed of a transverse wave, travelling on a wire having a length of 100 cm and mass 10 g is 160 m/s. The area of cross-section of the wire is 2 mm2 and its Young's modulus is 32×1011 N/m2. Find the extension of the wire from its natural length.

A capacitor of 10 μF and an inductor of 1 H are joined in series. An AC of 50 Hz is applied to this combination. What is the impedance of the combination?

Two blocks are placed over a rough pulley of moment of inertia I. When the block of mass M comes down by a distance h, the angular speed of the pulley is

A uniform chain of length l and mass m overhangs a smooth table with two third part lying on the table. Find the kinetic energy of the chain as it completely slips off the table.

What is the output Y in the following circuit when all the three inputs A, B, C are first 0 and then 1 ?

Can 2 equation having same unit must have same dimrdimens? If all terms have same dimensions,is it necessary that they have same units.

A 12-volt car battery can deliver a total charge of 100 ampere-hours. Using this battery how many 100 µF capacitors can be fully charged?

The potential energy of a particle of mass 1 kg moving along the X-axis is given by U=4(1+cos2x) J, where x is in meters. Find the time period of small oscillation (in second).

A U tube contains water and methylated spirit separated by mercury. The mercury columns in the two arms are at the same level with 10cm of water in one arm and 12.5cm of spirit in the other as shown in figure. The relative density of the spirit is

Two long conductors separated by a distance d carry currents i1 and i2 in the same direction. They exert a force F on each other. Now the current in one of them is increased to two times and its direction is reversed. The distance is also increased to 3d. The new value of the force between them is

The magnetic field due to a straight conductor of uniform cross section of radius a and carrying a steady current is represented by

Light is incident from glass (μ=1.5) to air. Sketch the variation of the angle of deviation δ with the angle of incident i for 0<i<90∘.

Consider the four processes A,B,C,D shown in the graph given below List I shows process & List II gives value of index ′n′ for the equation PVn=const Match List I with list II. List IList IIA.A1.0BB21CC3.1.4DD4.∞

Two waves represented by equation y1=Asin(ωt−kx+ϕ1) and y2=Asin(ωt−kx+ϕ2) are superimposed such that the amplitude of resultant wave is A. Find the phase difference between them. Given: (ϕ1>ϕ2)