50278 + Interview Questions in Physics

1.	A stone is projected from a horizontal plane. It attains maximum height ′H′ & strikes a stationary smooth wall & falls on the ground vertically below the maximum height. Assume the collision to be elastic, the height of the point on the wall where ball will strike is(Elastic collision means that after colliding on a plane the perpendicular component of the velocity before collision gets reversed after the collision. Here vx is normal to plane)
Answer» A stone is projected from a horizontal plane. It attains maximum height $^{'} H^{'}$ & strikes a stationary smooth wall & falls on the ground vertically below the maximum height. Assume the collision to be elastic, the height of the point on the wall where ball will strike is (Elastic collision means that after colliding on a plane the perpendicular component of the velocity before collision gets reversed after the collision. Here $v_{x}$ is normal to plane)

1.

A stone is projected from a horizontal plane. It attains maximum height ′H′ & strikes a stationary smooth wall & falls on the ground vertically below the maximum height. Assume the collision to be elastic, the height of the point on the wall where ball will strike is(Elastic collision means that after colliding on a plane the perpendicular component of the velocity before collision gets reversed after the collision. Here vx is normal to plane)

Answer»

A stone is projected from a horizontal plane. It attains maximum height $^{'} H^{'}$ & strikes a stationary smooth wall & falls on the ground vertically below the maximum height. Assume the collision to be elastic, the height of the point on the wall where ball will strike is

(Elastic collision means that after colliding on a plane the perpendicular component of the velocity before collision gets reversed after the collision. Here $v_{x}$ is normal to plane)

2.	A block of mass 4 kg is at rest on a frictionless horizontal surface. A horizontal force as a function of displacement as shown in graph acts on block. Speed of block when it has displaced by 6m is (Write two digits after the decimal point.)
Answer» A block of mass 4 kg is at rest on a frictionless horizontal surface. A horizontal force as a function of displacement as shown in graph acts on block. Speed of block when it has displaced by 6m is (Write two digits after the decimal point.)

3.	You slapped someone.( Or shook hands with them) what kind of fundamental force was at play here?
Answer» You slapped someone.( Or shook hands with them) what kind of fundamental force was at play here?

4.	In the arrangement shown below, all surfaces are smooth. The masses of blocks A and B are same. Find the distance moved by A in 1 second in horizontal direction, with respect to B if θ=300
Answer» In the arrangement shown below, all surfaces are smooth. The masses of blocks $A$ and $B$ are same. Find the distance moved by $A$ in $1 second$ in horizontal direction, with respect to $B$ if $θ = 30^{0}$

5.	A gas containing hydrogen like ions with atomic no. Z, emits photons in transition n+2→n, where n=Z. These photons fall on a metallic plate and eject electrons having minimum de-Broglie wavelength λ of 5A∘. Find the value of ‘Z′ if the work function of metal is 4.2 eV.
Answer» A gas containing hydrogen like ions with atomic no. Z, emits photons in transition $n + 2 \to n$ , where $n = Z$ . These photons fall on a metallic plate and eject electrons having minimum de-Broglie wavelength $λ$ of $5 A^{\circ}$ . Find the value of $‘ Z^{'}$ if the work function of metal is $4.2 eV$ .

6.	The point charges +1C, +1C and -1C are placed at the vertices A, B and C of an equilateral triangle of side 1 m. Then(A) The force acting on the charge at A is 910^9 N(B) The electric field strength at A is 910^9 NC-11) A is correct but B is wrong2) B is correct but A is wrong3) Both A and B are wrong4) Both A and B are correct
Answer» The point charges +1C, +1C and -1C are placed at the vertices A, B and C of an equilateral triangle of side 1 m. Then (A) The force acting on the charge at A is 910^9 N (B) The electric field strength at A is 910^9 NC-1 1) A is correct but B is wrong 2) B is correct but A is wrong 3) Both A and B are wrong 4) Both A and B are correct

7.	A circuit consists of two unequal resistance connected in parallel. Select the correct statement among the following.
Answer» A circuit consists of two unequal resistance connected in parallel. Select the correct statement among the following.

8.	A glass slab (μ=1.5) of thickness 4 cm is pressed against newspaper, the distance by which letter of the paper are seen raised against the paper by someone who is looking at letters along normal to the slab is
Answer» A glass slab ( $μ = 1.5)$ of thickness $4 cm$ is pressed against newspaper, the distance by which letter of the paper are seen raised against the paper by someone who is looking at letters along normal to the slab is

9.	A wheel has six equally spaced thin spokes of length 20 cm. It is rotating about an axis xx' which is perpendicular to its plane and passing through its center with 5 rev/sec. What should be the minimum velocity of an arrow of length 30 cm to pass the wheel without hitting any spoke. (Arrow is projected parallel to the axis).
Answer» A wheel has six equally spaced thin spokes of length $20 cm$ . It is rotating about an axis $xx'$ which is perpendicular to its plane and passing through its center with $5 rev/sec$ . What should be the minimum velocity of an arrow of length $30 cm$ to pass the wheel without hitting any spoke. (Arrow is projected parallel to the axis).

10.	6.Consider the arrangement shown in the figure in which the North pole of a magnet is moved away from a thick conducting loop containing a capacitor. Then excess positive charge will arrive on
Answer» 6.Consider the arrangement shown in the figure in which the North pole of a magnet is moved away from a thick conducting loop containing a capacitor. Then excess positive charge will arrive on

11.	if error in momentum of a given object is 10% then what is error in kinetic energy ?
Answer» if error in momentum of a given object is 10% then what is error in kinetic energy ?

13.	two spherical bodies of equal mass (M) revolve about their centre of mass. The distance between the centre of two masses is r. The angular momentum of each about their centre of mass is?
Answer» two spherical bodies of equal mass (M) revolve about their centre of mass. The distance between the centre of two masses is r. The angular momentum of each about their centre of mass is?

14.	A screw gauge gives the following reading for measuring the diameter of a wire.Main scale reading : 0 mmCircular scale reading : 60 divisionsGiven, that 1 mm on main scale corresponds to 100 divisions on circular scale. The diameter of wire is,
Answer» A screw gauge gives the following reading for measuring the diameter of a wire. Main scale reading : $0 mm$ Circular scale reading : $60$ divisions Given, that $1 mm$ on main scale corresponds to $100$ divisions on circular scale. The diameter of wire is,

15.	200 g of ice at −20∘C is mixed with 500 g of water at 20∘C in an insulating vessel. What is the final mass of water in the vessel? (Specific heat of ice =0.5 cal g−1∘C−1).
Answer» $200 g$ of ice at $- 20^{\circ} C$ is mixed with $500 g$ of water at $20^{\circ} C$ in an insulating vessel. What is the final mass of water in the vessel? (Specific heat of ice $= 0.5 {cal g}^{- 1}$ $^{\circ} C^{- 1}$ ).

16.	In the Saturn ring, rocks are orbiting in circular orbits. If maximum speed of the rocks is 10% more than minimum speed, then ratio of width of the ring to the inner radius of ring is (Write upto two digits after the decimal point)
Answer» In the Saturn ring, rocks are orbiting in circular orbits. If maximum speed of the rocks is 10% more than minimum speed, then ratio of width of the ring to the inner radius of ring is (Write upto two digits after the decimal point)

17.	32.Show that whenever two conductors share charges by bringing them into electrical contact, there is a loss of energy
Answer» 32.Show that whenever two conductors share charges by bringing them into electrical contact, there is a loss of energy

18.	The equation of motion of a particle of mass 1 g is d2xdt2+π2x=0, where x is displacement (in m) from mean position and t is in seconds. The frequency (in Hz) of oscillation is
Answer» The equation of motion of a particle of mass $1 g$ is $\frac{d^{2} x}{d t^{2}} + π^{2} x = 0$ , where $x$ is displacement (in $m$ ) from mean position and $t$ is in $seconds$ . The frequency (in $Hz$ ) of oscillation is

19.	Orange light of wavelength 6000×10–10 m illuminates a single slit of width 0.6×10–4 m. The maximum possible number of diffraction minima produced on both sides of the central maximum is
Answer» Orange light of wavelength $6000 \times 10^{- 10} m$ illuminates a single slit of width $0.6 \times 10^{- 4} m$ . The maximum possible number of diffraction minima produced on both sides of the central maximum is

20.	A sound wave has a time period of 0.5 s. How many times does a particle pass through a given point in one second?
Answer» A sound wave has a time period of $0.5 s$ . How many times does a particle pass through a given point in one second?

21.	23. if power factor is 1/2 in a series RL circuit, R = 100ohm, then L is (f= 50 Hz)
Answer» 23. if power factor is 1/2 in a series RL circuit, R = 100ohm, then L is (f= 50 Hz)

22.	A jet airplane travelling at the speed of 500kmh−1 ejects its products of combustion at the speed of 1500kmh−1 relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is:
Answer» A jet airplane travelling at the speed of $500 k m h^{- 1}$ ejects its products of combustion at the speed of $1500 k m h^{- 1}$ relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is:

23.	A solid cylinder of mass 50Kg and radius 0.5m is free to rotate about the horizontal axis a massless string is wound round the cylinder with one end attached to it and other hanging freely tension in the string required to produce an angular acceleration of 2rev/s^{2 is
Answer» A solid cylinder of mass 50Kg and radius 0.5m is free to rotate about the horizontal axis a massless string is wound round the cylinder with one end attached to it and other hanging freely tension in the string required to produce an angular acceleration of 2rev/s^{2 is

24.	A ray of light is incident on a glass plate making an angle of 60∘ with the normal to the surface at the point of projection. If the reflected ray and refracted rays are perpendicular to each other, the refractive index of glass is :
Answer» A ray of light is incident on a glass plate making an angle of $60^{\circ}$ with the normal to the surface at the point of projection. If the reflected ray and refracted rays are perpendicular to each other, the refractive index of glass is :

25.	Can anyone please help me out with time dilation and how aging which is a biological clock gets affected with time dilation I mean how can it be that a person is of 70 years on earth whereas abother person on a space ship is of 50 at the same time
Answer» Can anyone please help me out with time dilation and how aging which is a biological clock gets affected with time dilation I mean how can it be that a person is of 70 years on earth whereas abother person on a space ship is of 50 at the same time

26.	Two charges q and -2q are kept on a straight line. The number of points on this line where the electric potential is zero is?
Answer» Two charges q and -2q are kept on a straight line. The number of points on this line where the electric potential is zero is?

Explore topic-wise InterviewSolutions in Current Affairs.

A block of mass 4 kg is at rest on a frictionless horizontal surface. A horizontal force as a function of displacement as shown in graph acts on block. Speed of block when it has displaced by 6m is (Write two digits after the decimal point.)

You slapped someone.( Or shook hands with them) what kind of fundamental force was at play here?

In the arrangement shown below, all surfaces are smooth. The masses of blocks A and B are same. Find the distance moved by A in 1 second in horizontal direction, with respect to B if θ=300

A gas containing hydrogen like ions with atomic no. Z, emits photons in transition n+2→n, where n=Z. These photons fall on a metallic plate and eject electrons having minimum de-Broglie wavelength λ of 5A∘. Find the value of ‘Z′ if the work function of metal is 4.2 eV.

A circuit consists of two unequal resistance connected in parallel. Select the correct statement among the following.

A glass slab (μ=1.5) of thickness 4 cm is pressed against newspaper, the distance by which letter of the paper are seen raised against the paper by someone who is looking at letters along normal to the slab is

6.Consider the arrangement shown in the figure in which the North pole of a magnet is moved away from a thick conducting loop containing a capacitor. Then excess positive charge will arrive on

if error in momentum of a given object is 10% then what is error in kinetic energy ?

For the data given below.Distance (from originTime (in minutes) 0 km 9:00 a.m. 10 km 9:30 a.m. 20 km 10:00 a.m. 40 km 10:30 a.m.Select the graph that most appropriately represents the above data.

two spherical bodies of equal mass (M) revolve about their centre of mass. The distance between the centre of two masses is r. The angular momentum of each about their centre of mass is?

A screw gauge gives the following reading for measuring the diameter of a wire.Main scale reading : 0 mmCircular scale reading : 60 divisionsGiven, that 1 mm on main scale corresponds to 100 divisions on circular scale. The diameter of wire is,

200 g of ice at −20∘C is mixed with 500 g of water at 20∘C in an insulating vessel. What is the final mass of water in the vessel? (Specific heat of ice =0.5 cal g−1∘C−1).

In the Saturn ring, rocks are orbiting in circular orbits. If maximum speed of the rocks is 10% more than minimum speed, then ratio of width of the ring to the inner radius of ring is (Write upto two digits after the decimal point)

32.Show that whenever two conductors share charges by bringing them into electrical contact, there is a loss of energy

The equation of motion of a particle of mass 1 g is d2xdt2+π2x=0, where x is displacement (in m) from mean position and t is in seconds. The frequency (in Hz) of oscillation is

Orange light of wavelength 6000×10–10 m illuminates a single slit of width 0.6×10–4 m. The maximum possible number of diffraction minima produced on both sides of the central maximum is

A sound wave has a time period of 0.5 s. How many times does a particle pass through a given point in one second?

23. if power factor is 1/2 in a series RL circuit, R = 100ohm, then L is (f= 50 Hz)

A jet airplane travelling at the speed of 500kmh−1 ejects its products of combustion at the speed of 1500kmh−1 relative to the jet plane. The speed of the products of combustion with respect to an observer on the ground is:

A solid cylinder of mass 50Kg and radius 0.5m is free to rotate about the horizontal axis a massless string is wound round the cylinder with one end attached to it and other hanging freely tension in the string required to produce an angular acceleration of 2rev/s^{2 is

A ray of light is incident on a glass plate making an angle of 60∘ with the normal to the surface at the point of projection. If the reflected ray and refracted rays are perpendicular to each other, the refractive index of glass is :

Can anyone please help me out with time dilation and how aging which is a biological clock gets affected with time dilation I mean how can it be that a person is of 70 years on earth whereas abother person on a space ship is of 50 at the same time

Two charges q and -2q are kept on a straight line. The number of points on this line where the electric potential is zero is?

A particle of charge q and mass m is moving with a velocity −v^i(v≠0) towards a large screen placed in the (Y−Z) plane at a distance d. If there is a magnetic field →B=B0^k, the maximum value of v for which the particle will not hit the screen is :

An object can have acceleration, but constant velocity.Why is it not possible?

A particle is fired at an angle of 30∘ to the horizontal such that the vertical component of its initial velocity is 80 m/s. Its time of flight is T. Its velocity at t=T4 has a magnitude of nearly(Take g=10 m/s2)

A magnetising field of 2*10^3 produces a magnetic flux density 8 pi tesla in an iron rod the relative permeability of rod will be

a poimt charge is projected im a uniform magnetic field such that its velocity vector makes an angle of 30 eith magnetic field then path followed by particle wi

A particle move along the parabolic path, x = y^2 + 2y + 2 in such a way that the y-component of velocity vector remain 5 m/s during the motion. The magnitude of the acceleration of the particle is

A 0.01m aqueous solution of K3[Fe(CN)6] was found to freeze at –0.062∘C. If Kf for water is 1.86∘C /molal then the apparent percentage of dissociation is:

If I drop a ball from a height of 5 m then how long will it take to reach the ground?

a ball is moving with the velocity of 20 m/s collide with the smooth surface as showen in the fig the magnitude of change in velocity of the ball

If I0 is the intensity of the principle maximum in the single slit diffraction pattern, then what will be its intensity when the slit width is doubled ?

In a cinema hall, the charge per person is Rs.200. On the first day, only 60% of the seats were filled. The owner decided to reduce the price by 20% and there was in increase of 50% in the number of spectators on the next day. The percentage increase in the revenue on the second day was

A solid cylinder of mass M and radius R rolls without slipping down an inclined plane of length L and height h. What is the speed of its centre of mass when the cylinder reaches its bottom ?

The friction of the air causes vertical retardation equal to one tenth of the acceleration due to gravity (Take g = 10ms−2). The time of flight will be decreased by

A pendulum clock that keeps correct time on the earth is taken to the moon. It will run,

Consider the truss shown in figure below:The degree of static indeterminacy of the above shown truss is0

Two particles of masses 4 kg &amp; 2 kg are located as shown in the figure. The position of the centre of mass of the given system is (cos37∘=45 )

Two planets move around the sun. The periodic times and the mean radii of the orbits are T1,T2 and r1,r2 respectively. The ratio T1T2 is equal to

what is meant by law of inerti

Does Archimedes principle hold for a vessel in free fall or in a satellite moving in a circular orbit?

A uniform rod follows motion as shown in figure. Angular speed of the rod is

Two particles of masses 4 kg & 2 kg are located as shown in the figure. The position of the centre of mass of the given system is (cos37∘=45 )

27.	A particle of charge q and mass m is moving with a velocity −v^i(v≠0) towards a large screen placed in the (Y−Z) plane at a distance d. If there is a magnetic field →B=B0^k, the maximum value of v for which the particle will not hit the screen is :
Answer» A particle of charge $q$ and mass $m$ is moving with a velocity $- v^i (v \neq 0)$ towards a large screen placed in the $(Y - Z)$ plane at a distance $d$ . If there is a magnetic field $\to B = B_{0}^k$ , the maximum value of $v$ for which the particle will not hit the screen is :

28.	An object can have acceleration, but constant velocity.Why is it not possible?
Answer» An object can have acceleration, but constant velocity. Why is it not possible?

29.	A man is planning to go out with his friends in a car of mass 1500 kg via roadway. The road contains a hump of radius of curvature 30 m. Each of the friends including the man weighs an average of 80 kg. A force more than 5000 N will damage the car seriously. If he plans to go at a maximum speed of 15 m/s, what is the maximum number of people that can ride in the car?
Answer» A man is planning to go out with his friends in a car of mass $1500 kg$ via roadway. The road contains a hump of radius of curvature $30 m$ . Each of the friends including the man weighs an average of $80 kg$ . A force more than $5000 N$ will damage the car seriously. If he plans to go at a maximum speed of $15 m/s$ , what is the maximum number of people that can ride in the car?

30.	A particle is fired at an angle of 30∘ to the horizontal such that the vertical component of its initial velocity is 80 m/s. Its time of flight is T. Its velocity at t=T4 has a magnitude of nearly(Take g=10 m/s2)
Answer» A particle is fired at an angle of $30^{\circ}$ to the horizontal such that the vertical component of its initial velocity is $80 m / s$ . Its time of flight is $T$ . Its velocity at $t = \frac{T}{4}$ has a magnitude of nearly (Take $g = 10 m / s^{2}$ )

31.	Consider a water tank as shown in the figure. Its cross-sectional area is 0.4 m2. The tank has an opening B near the bottom whose cross-sectional area is 1 cm2. A load of 24 kg is applied on the water at the top when the height of the water level is 40 cm above the bottom, the velocity of water coming out from the opening B is v ms−1. The value of v, to the nearest integer, is _______.(g=10 m/s2)
Answer» Consider a water tank as shown in the figure. Its cross-sectional area is $0.4 m^{2}$ . The tank has an opening $B$ near the bottom whose cross-sectional area is $1 {cm}^{2}$ . A load of $24 kg$ is applied on the water at the top when the height of the water level is $40 cm$ above the bottom, the velocity of water coming out from the opening $B$ is $v {ms}^{- 1}$ . The value of $v$ , to the nearest integer, is _______. $(g = 10 {m/s}^{2})$

32.	A magnetising field of 2*10^3 produces a magnetic flux density 8 pi tesla in an iron rod the relative permeability of rod will be
Answer» A magnetising field of 2*10^3 produces a magnetic flux density 8 pi tesla in an iron rod the relative permeability of rod will be

33.	In a sonometer wire, the tension is maintained by suspended a 50.7 kg mass from the free end of the wire. The suspended mass has a volume of 0.0075 m3. The fundamental frequency of vibration of the wire is 260 Hz. If the suspended mass is completely submerged in water, the fundamental frequency will become Hz.
Answer» In a sonometer wire, the tension is maintained by suspended a $50.7 kg$ mass from the free end of the wire. The suspended mass has a volume of $0.0075 m^{3}$ . The fundamental frequency of vibration of the wire is $260 Hz$ . If the suspended mass is completely submerged in water, the fundamental frequency will become $Hz$ .

34.	a poimt charge is projected im a uniform magnetic field such that its velocity vector makes an angle of 30 eith magnetic field then path followed by particle wi
Answer» a poimt charge is projected im a uniform magnetic field such that its velocity vector makes an angle of 30 eith magnetic field then path followed by particle wi

35.	A particle move along the parabolic path, x = y^2 + 2y + 2 in such a way that the y-component of velocity vector remain 5 m/s during the motion. The magnitude of the acceleration of the particle is
Answer» A particle move along the parabolic path, x = y^2 + 2y + 2 in such a way that the y-component of velocity vector remain 5 m/s during the motion. The magnitude of the acceleration of the particle is

36.	A 0.01m aqueous solution of K3[Fe(CN)6] was found to freeze at –0.062∘C. If Kf for water is 1.86∘C /molal then the apparent percentage of dissociation is:
Answer» A 0.01m aqueous solution of $K_{3} [F e (C N)_{6}]$ was found to freeze at $- {0.062}^{\circ} C$ . If Kf for water is ${1.86}^{\circ} C$ /molal then the apparent percentage of dissociation is: