50278 + Interview Questions in Physics Page 294 InterviewSolution

14651.	A cord is wound around the circumference of a bicycle wheel (without tyre) of diameter 1 m. A mass of 2 kg is tied to the end of the cord and it s allowed to fall from rest. The weight falls 2 m in 4 s. The axle of the wheel is horizontal and the wheel rotates with its plane vertical. The angular acceleration produced is (Take g=10 ms−2)
Answer» A cord is wound around the circumference of a bicycle wheel (without tyre) of diameter $1 m$ . A mass of $2 kg$ is tied to the end of the cord and it s allowed to fall from rest. The weight falls $2 m$ in $4 s$ . The axle of the wheel is horizontal and the wheel rotates with its plane vertical. The angular acceleration produced is (Take $g = 10 {ms}^{- 2}$ )

Discussion

14652.	Look at the figure given below:Without which of the following forces listed below, the person would not be able to climb the wall?
Answer» Look at the figure given below: Without which of the following forces listed below, the person would not be able to climb the wall?

Discussion

14653.	Agalvanometer coil has a resistance of 12 Ω andthe metre shows full scale deflection for a current of 3 mA. How willyou convert the metre into a voltmeter of range 0 to 18 V?
Answer» A galvanometer coil has a resistance of 12 Ω and the metre shows full scale deflection for a current of 3 mA. How will you convert the metre into a voltmeter of range 0 to 18 V?

Discussion

14654.	The time period of a freely suspended bar magnet is 4 s. If it is broken in length into two equal parts and one part is suspended the same way, new time period will be
Answer» The time period of a freely suspended bar magnet is 4 s. If it is broken in length into two equal parts and one part is suspended the same way, new time period will be

Discussion

14655.	Particle A of mass m experiences a perfectly elastic collision with a stationary particle B of mass M. After the collision (head-on) the particles fly apart in opposite directions with equal velocities. Then:
Answer» Particle A of mass m experiences a perfectly elastic collision with a stationary particle B of mass M. After the collision (head-on) the particles fly apart in opposite directions with equal velocities. Then:

Discussion

14656.	A particle is suspended by a light rod of length l. Minimum speed with which the particle should be projected,so that it moves in a vertical circle
Answer» A particle is suspended by a light rod of length l. Minimum speed with which the particle should be projected,so that it moves in a vertical circle

Discussion

14657.	Two waves are propagating to the point P along a straight line produced by two sources A and B which are simple harmonic in nature and of equal frequency. The amplitude of every wave at P is a and the phase of A is π3 ahead that of B and the distance AP is greater than BP by 50 cm. Then, the resultant amplitude at that point P will be xa (wavelength is 1 meter) then the value of x is
Answer» Two waves are propagating to the point $P$ along a straight line produced by two sources $A$ and $B$ which are simple harmonic in nature and of equal frequency. The amplitude of every wave at $P$ is $a$ and the phase of $A$ is $\frac{π}{3}$ ahead that of $B$ and the distance $A P$ is greater than $B P$ by $50 c m$ . Then, the resultant amplitude at that point $P$ will be $x a$ (wavelength is 1 meter) then the value of $x$ is

Discussion

14658.	How cathode rays are deflected in magnetic field?
Answer» How cathode rays are deflected in magnetic field?

Discussion

14659.	At a metro station, a girl walks up a stationary escalator in time t1. If she remains stationary on the escalator, then the escalator take her up in time t2. The time taken by her to walk up on the moving escalator will be (a) (t1 + t2)/2 (c) t1t2/(t2+t1) (b) t1t2/(t2–t1) (d) t1–t2
Answer» At a metro station, a girl walks up a stationary escalator in time t1. If she remains stationary on the escalator, then the escalator take her up in time t2. The time taken by her to walk up on the moving escalator will be (a) (t1 + t2)/2 (c) t1t2/(t2+t1) (b) t1t2/(t2–t1) (d) t1–t2

Discussion

14660.	A coil has an inductance of 0.7 henryand is joined in series with a resistance of220ohm .When an AC source of 220V at 50Hz is applied to it, then the phase through which current lagsbehind the applied emf and the wattless componentof maximum current in the circuit will be
Answer» A coil has an inductance of 0.7 henryand is joined in series with a resistance of220ohm .When an AC source of 220V at 50Hz is applied to it, then the phase through which current lagsbehind the applied emf and the wattless componentof maximum current in the circuit will be

Discussion

14661.	A body is moving in a circular path of radius r with a cons†an t speed v then find out the average speed and average velocity in moving quarter circl
Answer» A body is moving in a circular path of radius r with a cons†an t speed v then find out the average speed and average velocity in moving quarter circl

Discussion

14662.	an astronaut jumps from a plane after he had fallen 40 m then his parachute opens now he falls with retardation of 2m/s2 reaches the earth with a velocity of 3m/s what's the height of the airplane? How long Astronaut remain in air? g= 9.8m/s2a
Answer» an astronaut jumps from a plane after he had fallen 40 m then his parachute opens now he falls with retardation of 2m/s² reaches the earth with a velocity of 3m/s what's the height of the airplane? How long Astronaut remain in air? g= 9.8m/s^2a

Discussion

14663.	Figure (5-E21) shows a man of mass 60 kg standing ona light weighing machine kept in a box of mass 30 kg.The box is hanging from a pulley fixed to the ceilingthrough a light rope, the other end of which is held bythe man himself. If the man manages to keep the boxat rest, what is the weight shown by the machine? Whatforce should he exert on the rope to get his correct weighton the machine?
Answer» Figure (5-E21) shows a man of mass 60 kg standing ona light weighing machine kept in a box of mass 30 kg.The box is hanging from a pulley fixed to the ceilingthrough a light rope, the other end of which is held bythe man himself. If the man manages to keep the boxat rest, what is the weight shown by the machine? Whatforce should he exert on the rope to get his correct weighton the machine?

Discussion

14664.	What was ancient Indian perspective on matter
Answer» What was ancient Indian perspective on matter

Discussion

14665.	Charges are placed on corners of square of side a (as shown in figure). Find magnitude of net dipole moment.
Answer» Charges are placed on corners of square of side $a$ (as shown in figure). Find magnitude of net dipole moment.

Discussion

14666.	A particle is projected from point o with velocity v1 at angle 30 degree with the horizontal and another paeticle is projected from point p which os vertically below the highest point with velocity v2 in the vertical upward direction For two particles to collide ythe raatio v1/v2will be
Answer» A particle is projected from point o with velocity v1 at angle 30 degree with the horizontal and another paeticle is projected from point p which os vertically below the highest point with velocity v2 in the vertical upward direction For two particles to collide ythe raatio v1/v2will be

Discussion

14667.	A body of mass m is situated at a distance 4R above the earth's surface, where R is the radius of earth. How much minimum energy be given to the body so that it may escape
Answer» A body of mass m is situated at a distance 4R above the earth's surface, where R is the radius of earth. How much minimum energy be given to the body so that it may escape

Discussion

14668.	Three concentric metallic spherical shells of radii R,2R,3R are given charges Q1,Q2,Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells Q1:Q2:Q3 is
Answer» Three concentric metallic spherical shells of radii $R, 2 R, 3 R$ are given charges $Q_{1}, Q_{2}, Q_{3}$ respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells $Q_{1} : Q_{2} : Q_{3}$ is

Discussion

14669.	ntA particle is moving with constant speed V along X axis in positive direction. Find the angular velocity of the particle about the point (0,b) when position of the particle is (a,0).n
Answer» ntA particle is moving with constant speed V along X axis in positive direction. Find the angular velocity of the particle about the point (0,b) when position of the particle is (a,0).n

Discussion

14670.	PL32. The time period of spring block system is T. Thespring is cut into two parts with their length in ratioof 2: 3. Find the time period of oscillation of sameblock with longer part of spring(2) 2т,ЗК(1) 2TKЗт2m(4) 2t5K(3) 2T5K
Answer» PL32. The time period of spring block system is T. Thespring is cut into two parts with their length in ratioof 2: 3. Find the time period of oscillation of sameblock with longer part of spring(2) 2т,ЗК(1) 2TKЗт2m(4) 2t5K(3) 2T5K

Discussion

14671.	Two identical balls are set into motion simultaneously from equal heights h. While the ball A is thrown horizontally with velocity v, the ball B is just released to fall by itself. Choose the alternative that best represents the motion of A and B with respect to an observer who moves with velocity v2 with respect to the ground as shown in the figure.
Answer» Two identical balls are set into motion simultaneously from equal heights h. While the ball $A$ is thrown horizontally with velocity $v$ , the ball $B$ is just released to fall by itself. Choose the alternative that best represents the motion of $A$ and $B$ with respect to an observer who moves with velocity $\frac{v}{2}$ with respect to the ground as shown in the figure.

14671.

Two identical balls are set into motion simultaneously from equal heights h. While the ball A is thrown horizontally with velocity v, the ball B is just released to fall by itself. Choose the alternative that best represents the motion of A and B with respect to an observer who moves with velocity v2 with respect to the ground as shown in the figure.

Answer»

Two identical balls are set into motion simultaneously from equal heights h. While the ball $A$ is thrown horizontally with velocity $v$ , the ball $B$ is just released to fall by itself. Choose the alternative that best represents the motion of $A$ and $B$ with respect to an observer who moves with velocity $\frac{v}{2}$ with respect to the ground as shown in the figure.

Discussion

14672.	The speed of the block when it reaches the point Q is
Answer» The speed of the block when it reaches the point $Q$ is

Discussion

14673.	The electric field of a plane electromagnetic wave is given by →E=E0(^x+^y)sin(kz−ωt).Its magnetic field will be given by :
Answer» The electric field of a plane electromagnetic wave is given by $\to E = E_{0} (^x +^y) sin (k z - ω t)$ . Its magnetic field will be given by :

Discussion

14674.	Determine the water equivalent of 4.5 kg of antimony. Take specific heat of antimony and water as 0.210 kJ/kg K and 4.20 kJ/kg K respectively.
Answer» Determine the water equivalent of $4.5 kg$ of antimony. Take specific heat of antimony and water as $0.210 kJ/kg K$ and $4.20 kJ/kg K$ respectively.

Discussion

14675.	two soap bubbles each of radius r ,coalesces to form a single bubble isothermally then the radius of bigger drop will be
Answer» two soap bubbles each of radius r ,coalesces to form a single bubble isothermally then the radius of bigger drop will be

Discussion

14676.	Point masses m1 and m2 are placed at the opposite ends of a rigid rod of length L,and negligeable mass. The rod is set rotating about an axis perpendicular to it. The position of point P on this rod through which axis should pass so that the work required to set the rod rotating with angular velocity w0(omega) is minimum, is given by
Answer» Point masses m1 and m2 are placed at the opposite ends of a rigid rod of length L,and negligeable mass. The rod is set rotating about an axis perpendicular to it. The position of point P on this rod through which axis should pass so that the work required to set the rod rotating with angular velocity w0(omega) is minimum, is given by

Discussion

14677.	A block is placed on an inclined plane of inclination θ. The angle of inclination is such that the block slides down the plane at a constant speed. The coefficient of kinetic friction between the block and the inclined plane is equal to
Answer» A block is placed on an inclined plane of inclination $θ$ . The angle of inclination is such that the block slides down the plane at a constant speed. The coefficient of kinetic friction between the block and the inclined plane is equal to

Discussion

14678.	Choose incorrect statement:
Answer» Choose incorrect statement:

Discussion

14679.	Why distance is always positive or zero?
Answer» Why distance is always positive or zero?

Discussion

14680.	A square plate of edge a2 is cut out from a uniform square plate of edge ′a′ as shown in the figure. The mass of the remaining portion is M. The moment of inertia of the remaining portion about an axis passing through 'O' (centre of the square of side a) and perpendicular to the plane of the plate is:
Answer» A square plate of edge $\frac{a}{2}$ is cut out from a uniform square plate of edge $^{'} a^{'}$ as shown in the figure. The mass of the remaining portion is $M$ . The moment of inertia of the remaining portion about an axis passing through $'O'$ (centre of the square of side $a$ ) and perpendicular to the plane of the plate is:

Discussion

14681.	A solid conducting sphere of radius 10 cm isenclosed by a thin metallic shell of radius 20 cm.A charge q= 20 uC is given to the inner sphere.The heat generated in the process when the inner sphere is connected to the shell by a conductingwire(2) 9 J(1) 12 J(4) Zero(3) 24 J
Answer» A solid conducting sphere of radius 10 cm isenclosed by a thin metallic shell of radius 20 cm.A charge q= 20 uC is given to the inner sphere.The heat generated in the process when the inner sphere is connected to the shell by a conductingwire(2) 9 J(1) 12 J(4) Zero(3) 24 J

Discussion

14682.	The graph shows relationship between object distance and image distance for an equiconvex lens. Then, focal length of the lens is
Answer» The graph shows relationship between object distance and image distance for an equiconvex lens. Then, focal length of the lens is

Discussion

14683.	23. How the electromagnet works and how the motor and generator rotate?
Answer» 23. How the electromagnet works and how the motor and generator rotate?

Discussion

14684.	A steel scale measures the length of a copper rod as L cm when both are at 20∘C, the calibration temperature for the scale. If the coefficients of linear expansion for steel and copper are αs and αc respectively, what would be the scale reading (in cm) when both are at 21∘C?
Answer» A steel scale measures the length of a copper rod as L cm when both are at $20^{\circ} C$ , the calibration temperature for the scale. If the coefficients of linear expansion for steel and copper are $α_{s}$ and $α_{c}$ respectively, what would be the scale reading (in cm) when both are at $21^{\circ} C$ ?

Discussion

14685.	4.A string 120cm in length sustains a standing wave with the points of the string at which the displacement amplitude is equal to 3.5mm being separated by 15cm. Find the maximum displacement amplitude. To which overtone do these oscillations correspond?
Answer» 4.A string 120cm in length sustains a standing wave with the points of the string at which the displacement amplitude is equal to 3.5mm being separated by 15cm. Find the maximum displacement amplitude. To which overtone do these oscillations correspond?

Discussion

14686.	A 4-pole, 3-phase, 400 V, 50 Hz induction motor has following parameters for its circuit model (referred to stator side on equivalent - star basis)r1=1.2 Ω x1=1.16 Ωr′2=0.4 Ω x′2=1.16 ΩXm=35 Ωfor a speed of 1440 rpm, the input current to the motor is _____A. 21.09
Answer» A 4-pole, 3-phase, 400 V, 50 Hz induction motor has following parameters for its circuit model (referred to stator side on equivalent - star basis) $r_{1} = 1.2 Ω$ $x_{1} = 1.16 Ω$ $r_{2}^{'} = 0.4 Ω$ $x_{2}^{'} = 1.16 Ω$ $X_{m} = 35 Ω$ for a speed of 1440 rpm, the input current to the motor is _____A. 21.09

Discussion

14687.	A simple pendulum of length l and bob ofmass m is hanging in front of a large nonconducting sheet having surface charge density p.if suddenly a charge +q is given to thebob and it is released from themeanposition.find the maximum angle thru which the string is deflected from vertical.
Answer» A simple pendulum of length l and bob ofmass m is hanging in front of a large nonconducting sheet having surface charge density p.if suddenly a charge +q is given to thebob and it is released from themeanposition.find the maximum angle thru which the string is deflected from vertical.

Discussion

14688.	Why is PV work negative ? Answer me more clearly please sir/mam.
Answer» Why is PV work negative ? Answer me more clearly please sir/mam.

Discussion

14689.	Calculate the amount of carbon which on combustion gives 56 litre of CO2?
Answer» Calculate the amount of carbon which on combustion gives 56 litre of CO2?

Discussion

14690.	Given graph shows electric field intensity due to a point charge (E) at a distance (x) from it.Here graphs(A,B,C,D) corresponding to four charges are shown. Which graph represents the charge of higher magnitude?
Answer» Given graph shows electric field intensity due to a point charge $(E)$ at a distance $(x)$ from it. Here graphs $(A, B, C, D)$ corresponding to four charges are shown. Which graph represents the charge of higher magnitude?

Discussion

14691.	When a long glass capillary tube of radius 0.015 cm is dipped in a liquid, the liquid rises to a height of 15 cm within it. If the contact angle between the liquid and glass to close to 0∘, the surface tension of the liquid (in mN m−1) is ______. (Give answer in the closest integer)[ρ(liquid)=900 kg m−3, g=10 ms−2]
Answer» When a long glass capillary tube of radius $0.015 cm$ is dipped in a liquid, the liquid rises to a height of $15 cm$ within it. If the contact angle between the liquid and glass to close to $0^{\circ},$ the surface tension of the liquid (in ${mN m}^{- 1}$ ) is ______. (Give answer in the closest integer) [ $ρ_{(liquid)} = 900 {kg m}^{- 3}, g = 10 {ms}^{- 2}$ ]

Discussion

14692.	The mathematical proof of mean value of an alternative current.
Answer» The mathematical proof of mean value of an alternative current.

Discussion

14693.	the vernier scale of a callipers has 50 divisions which coincide with 49 main scale divisions.if each main scale division is of 0.5 mm,then the minimum inaccura cy in the measurement by calliers is ?
Answer» the vernier scale of a callipers has 50 divisions which coincide with 49 main scale divisions.if each main scale division is of 0.5 mm,then the minimum inaccura cy in the measurement by calliers is ?

Discussion

14694.	A particle of mass m is projected with a speed u at an angle θ with the horizontal. Find the torque of the weight of the particle about the point of projection when the particle is at the highest point.
Answer» A particle of mass m is projected with a speed u at an angle $θ$ with the horizontal. Find the torque of the weight of the particle about the point of projection when the particle is at the highest point.

Discussion

14695.	A particle is thrown vertically upwards. It's velocity at half of the height is 10 m/s, then the maximum height attained by it will be:
Answer» A particle is thrown vertically upwards. It's velocity at half of the height is $10 m/s$ , then the maximum height attained by it will be:

Discussion

14696.	A lens of focal length f forms an image of magnification n, The distance of object from the lens in terms of f and n is
Answer» A lens of focal length $f$ forms an image of magnification $n$ , The distance of object from the lens in terms of $f$ and $n$ is

Discussion

14697.	The net torque created by a force couple is
Answer» The net torque created by a force couple is

Discussion

14698.	Through which of the spheres, net electric flux is zero?
Answer» Through which of the spheres, net electric flux is zero?

Discussion

14699.	The potential energy of an electron in hydrogen atom is -3.02 it's kinetic energy will be
Answer» The potential energy of an electron in hydrogen atom is -3.02 it's kinetic energy will be

Discussion

14700.	38.The order of density in nucleus is(in kg/cc)-
Answer» 38.The order of density in nucleus is(in kg/cc)-

Discussion

Explore topic-wise InterviewSolutions in .

Look at the figure given below:Without which of the following forces listed below, the person would not be able to climb the wall?

Agalvanometer coil has a resistance of 12 Ω andthe metre shows full scale deflection for a current of 3 mA. How willyou convert the metre into a voltmeter of range 0 to 18 V?

The time period of a freely suspended bar magnet is 4 s. If it is broken in length into two equal parts and one part is suspended the same way, new time period will be

Particle A of mass m experiences a perfectly elastic collision with a stationary particle B of mass M. After the collision (head-on) the particles fly apart in opposite directions with equal velocities. Then:

A particle is suspended by a light rod of length l. Minimum speed with which the particle should be projected,so that it moves in a vertical circle

How cathode rays are deflected in magnetic field?

At a metro station, a girl walks up a stationary escalator in time t1. If she remains stationary on the escalator, then the escalator take her up in time t2. The time taken by her to walk up on the moving escalator will be (a) (t1 + t2)/2 (c) t1t2/(t2+t1) (b) t1t2/(t2–t1) (d) t1–t2

A coil has an inductance of 0.7 henryand is joined in series with a resistance of220ohm .When an AC source of 220V at 50Hz is applied to it, then the phase through which current lagsbehind the applied emf and the wattless componentof maximum current in the circuit will be

A body is moving in a circular path of radius r with a cons†an t speed v then find out the average speed and average velocity in moving quarter circl

an astronaut jumps from a plane after he had fallen 40 m then his parachute opens now he falls with retardation of 2m/s2 reaches the earth with a velocity of 3m/s what's the height of the airplane? How long Astronaut remain in air? g= 9.8m/s2a

What was ancient Indian perspective on matter

Charges are placed on corners of square of side a (as shown in figure). Find magnitude of net dipole moment.

A particle is projected from point o with velocity v1 at angle 30 degree with the horizontal and another paeticle is projected from point p which os vertically below the highest point with velocity v2 in the vertical upward direction For two particles to collide ythe raatio v1/v2will be

A body of mass m is situated at a distance 4R above the earth's surface, where R is the radius of earth. How much minimum energy be given to the body so that it may escape

Three concentric metallic spherical shells of radii R,2R,3R are given charges Q1,Q2,Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells Q1:Q2:Q3 is

ntA particle is moving with constant speed V along X axis in positive direction. Find the angular velocity of the particle about the point (0,b) when position of the particle is (a,0).n

PL32. The time period of spring block system is T. Thespring is cut into two parts with their length in ratioof 2: 3. Find the time period of oscillation of sameblock with longer part of spring(2) 2т,ЗК(1) 2TKЗт2m(4) 2t5K(3) 2T5K

The speed of the block when it reaches the point Q is

The electric field of a plane electromagnetic wave is given by →E=E0(^x+^y)sin(kz−ωt).Its magnetic field will be given by :

Determine the water equivalent of 4.5 kg of antimony. Take specific heat of antimony and water as 0.210 kJ/kg K and 4.20 kJ/kg K respectively.

two soap bubbles each of radius r ,coalesces to form a single bubble isothermally then the radius of bigger drop will be

A block is placed on an inclined plane of inclination θ. The angle of inclination is such that the block slides down the plane at a constant speed. The coefficient of kinetic friction between the block and the inclined plane is equal to

Choose incorrect statement:

Why distance is always positive or zero?

A solid conducting sphere of radius 10 cm isenclosed by a thin metallic shell of radius 20 cm.A charge q= 20 uC is given to the inner sphere.The heat generated in the process when the inner sphere is connected to the shell by a conductingwire(2) 9 J(1) 12 J(4) Zero(3) 24 J

The graph shows relationship between object distance and image distance for an equiconvex lens. Then, focal length of the lens is

23. How the electromagnet works and how the motor and generator rotate?

A steel scale measures the length of a copper rod as L cm when both are at 20∘C, the calibration temperature for the scale. If the coefficients of linear expansion for steel and copper are αs and αc respectively, what would be the scale reading (in cm) when both are at 21∘C?

4.A string 120cm in length sustains a standing wave with the points of the string at which the displacement amplitude is equal to 3.5mm being separated by 15cm. Find the maximum displacement amplitude. To which overtone do these oscillations correspond?

A 4-pole, 3-phase, 400 V, 50 Hz induction motor has following parameters for its circuit model (referred to stator side on equivalent - star basis)r1=1.2 Ω x1=1.16 Ωr′2=0.4 Ω x′2=1.16 ΩXm=35 Ωfor a speed of 1440 rpm, the input current to the motor is _____A. 21.09

A simple pendulum of length l and bob ofmass m is hanging in front of a large nonconducting sheet having surface charge density p.if suddenly a charge +q is given to thebob and it is released from themeanposition.find the maximum angle thru which the string is deflected from vertical.

Why is PV work negative ? Answer me more clearly please sir/mam.

Calculate the amount of carbon which on combustion gives 56 litre of CO2?

Given graph shows electric field intensity due to a point charge (E) at a distance (x) from it.Here graphs(A,B,C,D) corresponding to four charges are shown. Which graph represents the charge of higher magnitude?

The mathematical proof of mean value of an alternative current.

the vernier scale of a callipers has 50 divisions which coincide with 49 main scale divisions.if each main scale division is of 0.5 mm,then the minimum inaccura cy in the measurement by calliers is ?

A particle of mass m is projected with a speed u at an angle θ with the horizontal. Find the torque of the weight of the particle about the point of projection when the particle is at the highest point.

A particle is thrown vertically upwards. It's velocity at half of the height is 10 m/s, then the maximum height attained by it will be:

A lens of focal length f forms an image of magnification n, The distance of object from the lens in terms of f and n is

The net torque created by a force couple is

Through which of the spheres, net electric flux is zero?

The potential energy of an electron in hydrogen atom is -3.02 it's kinetic energy will be

38.The order of density in nucleus is(in kg/cc)-