13232 + Interview Questions in Physics Page 53 InterviewSolution

2601.	The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14. What is the number of electrons in the ion?
Answer» The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

Discussion

2602.	A circular disc of diameter 1 cm has been placed on the principal axis of a concave mirror (R=20 cm) with its plane perpendicular to the principal axis at a distance of 15 cm from the pole of the mirror. If the radius of disc starts increasing according to equation r=(0.5+0.1t) cm, where t is time in s, then what will be the rate at which radius of its image is increasing?
Answer» A circular disc of diameter $1 cm$ has been placed on the principal axis of a concave mirror $(R = 20 cm)$ with its plane perpendicular to the principal axis at a distance of $15 cm$ from the pole of the mirror. If the radius of disc starts increasing according to equation $r = (0.5 + 0.1 t) cm$ , where $t$ is time in $s$ , then what will be the rate at which radius of its image is increasing?

Discussion

2603.	what does this mean-when value of relativistic charged particle increases its specific charge remains same. what is relativistic charge??
Answer» what does this mean-when value of relativistic charged particle increases its specific charge remains same. what is relativistic charge??

Discussion

2604.	72.A particle accelerates from rest with constant acceleration a for m seconds . It's velocity at the end of m seconds is v. The displacement of the particle in last 3 seconds is ??
Answer» 72.A particle accelerates from rest with constant acceleration a for m seconds . It's velocity at the end of m seconds is v. The displacement of the particle in last 3 seconds is ??

Discussion

2605.	What is the buoyant force experienced by a cube of side 10 cm which is completely immersed in water?(Take g=10 m s−2 and density of water =1000 kg m−3)
Answer» What is the buoyant force experienced by a cube of side $10 c m$ which is completely immersed in water? (Take $g = 10 m s^{- 2}$ and density of water $= 1000 k g m^{- 3}$ )

Discussion

2606.	An object is kept at a distance of 16 cm from a thin lens and the image formed is real. If the object is kept at a distance of 6 cm from the same lens, the image formed is virtual. If the sizes of the images formed are equal, the focal length of the lens will be :
Answer» An object is kept at a distance of $16 cm$ from a thin lens and the image formed is real. If the object is kept at a distance of $6 cm$ from the same lens, the image formed is virtual. If the sizes of the images formed are equal, the focal length of the lens will be :

Discussion

2607.	When iron filings are spread on a piece of paper with a bar magnet kept below , the filings:
Answer» When iron filings are spread on a piece of paper with a bar magnet kept below , the filings:

Discussion

2608.	Write all the factors that affect fluid friction.
Answer» Write all the factors that affect fluid friction.

Discussion

2609.	Three forces are acting on a particle of mass m initially in equilibrium. If the first 2 forces (F1and F2) are perpendicular to each other and suddenly the third force F3 is removed, then findacceleration of the particle ?
Answer» Three forces are acting on a particle of mass m initially in equilibrium. If the first 2 forces (F1 and F2) are perpendicular to each other and suddenly the third force F3 is removed, then find acceleration of the particle ?

Discussion

2610.	Choose the most important natural source of energy from the following
Answer» Choose the most important natural source of energy from the following

Discussion

2611.	A student comments that the speed of object Q is decreasing and the speed of object P is increasing. State whether the comment is correct or incorrect.Justify your answer.
Answer» A student comments that the speed of object Q is decreasing and the speed of object P is increasing. State whether the comment is correct or incorrect. Justify your answer.

2611.

A student comments that the speed of object Q is decreasing and the speed of object P is increasing. State whether the comment is correct or incorrect.Justify your answer.

Answer»

A student comments that the speed of object Q is decreasing and the speed of object P is increasing. State whether the comment is correct or incorrect.

Justify your answer.

Discussion

2612.	When an electron goes in a straight line the electric flux first increases then decreases. HOW
Answer» When an electron goes in a straight line the electric flux first increases then decreases. HOW

Discussion

2613.	How to convert watt into Kilowatt and kilowatt into watt
Answer» How to convert watt into Kilowatt and kilowatt into watt

Discussion

2614.

The circuit given below consists of cells with their internal resistance(ii) The equivalent internal resistance of the combination is

Answer»

The circuit given below consists of cells with their internal resistance

(i i)

The equivalent internal resistance of the combination is

Discussion

2615.	Consider an ideal op-amp circuit shown in the figure below:The value of output voltage V0 is equal to
Answer» Consider an ideal op-amp circuit shown in the figure below: The value of output voltage $V_{0}$ is equal to

Discussion

2616.	Name the commercial unit of measurement of energy.
Answer» Name the commercial unit of measurement of energy.

Discussion

2617.	What are the steps to solve? The two ends of a train moving with cons†an t acceleration pass a certain point with velocities u and 3u. The velocity with which the middle point of the train passes the same point is
Answer» What are the steps to solve? The two ends of a train moving with cons†an t acceleration pass a certain point with velocities u and 3u. The velocity with which the middle point of the train passes the same point is

Discussion

2618.	What is the use of particle accelerator?
Answer» What is the use of particle accelerator?

Discussion

2619.	The distance between a compression and the immediate next rarefaction of a longitudinal wave is: (λ denotes wavelength)
Answer» The distance between a compression and the immediate next rarefaction of a longitudinal wave is: ( $λ$ denotes wavelength)

Discussion

2620.	Why Earth is called a unique planet?
Answer» Why Earth is called a unique planet?

Discussion

2621.	How is pressure related to the area over which a force acts?
Answer» How is pressure related to the area over which a force acts?

Discussion

2622.	A glass rod gets electrically charged on rubbing with silk cloth. What's the source of this charge?
Answer» A glass rod gets electrically charged on rubbing with silk cloth. What's the source of this charge?

Discussion

2623.	30.Derive the expression of velocity of an object thrown as a projectile at any point of its trajectory
Answer» 30.Derive the expression of velocity of an object thrown as a projectile at any point of its trajectory

Discussion

2624.	(42 The frequency changes by 10% as a sound sourceapproaches a stationary observer with constantspeed V, What would be percentage change inthe frequency as the source recedes the observerwith same speed (V. < V)?(1)10.5%(2) 8.5%(3) 4.5%(4)1.5%
Answer» (42 The frequency changes by 10% as a sound sourceapproaches a stationary observer with constantspeed V, What would be percentage change inthe frequency as the source recedes the observerwith same speed (V. < V)?(1)10.5%(2) 8.5%(3) 4.5%(4)1.5%

Discussion

2625.	25.An object is projected vertically upward with speed root gR where R is the radius of earth and g is acceleration due to gravity on the surface of earth. Find the maximum height attained by it.
Answer» 25.An object is projected vertically upward with speed root gR where R is the radius of earth and g is acceleration due to gravity on the surface of earth. Find the maximum height attained by it.

Discussion

2626.	A cube of unknown material supporting a 500 gm mass just sinks in water. When the mass is removed, the cube goes up by 4 cm. Then, the volume of the cube is
Answer» A cube of unknown material supporting a $500 gm$ mass just sinks in water. When the mass is removed, the cube goes up by $4 cm$ . Then, the volume of the cube is

Discussion

2627.	The atmosphere is held to the Earth due to:
Answer» The atmosphere is held to the Earth due to:

Discussion

2628.	APS 05 (MeAn object is projected with a velocity of 20 m/smaking an angle of 45^° with horizontal. Theequation for the trajectory is h = Ax - Bx2, whereh is height, x is horizontal distance, A and B areconstants. The ratio of A : B isues(1) 1:5(2) 5:1(3) 1:40(4) 40 1
Answer» APS 05 (MeAn object is projected with a velocity of 20 m/smaking an angle of 45^° with horizontal. Theequation for the trajectory is h = Ax - Bx2, whereh is height, x is horizontal distance, A and B areconstants. The ratio of A : B isues(1) 1:5(2) 5:1(3) 1:40(4) 40 1

Discussion

2629.	The scales - vernier callipers, metre scale and screw gauge has the least counts:
Answer» The scales - vernier callipers, metre scale and screw gauge has the least counts:

Discussion

2630.	the dis†an ce between three consecutive troughs ina wave produced in a string is4cm . if 2.5 wave cycles pass through any point in a second, the wave in the sttring ihas velocity a) 10 cm/s b) 0.16cm/s c) 0.8 cm/s d) 5 cm/s
Answer» the dis†an ce between three consecutive troughs ina wave produced in a string is4cm . if 2.5 wave cycles pass through any point in a second, the wave in the sttring ihas velocity a) 10 cm/s b) 0.16cm/s c) 0.8 cm/s d) 5 cm/s

Discussion

2631.	(3)U.370If mass of earth decreases by 25% and its radius increases by 50%, then acceleration due to gravity at itssurface decreases by nearly670
Answer» (3)U.370If mass of earth decreases by 25% and its radius increases by 50%, then acceleration due to gravity at itssurface decreases by nearly670

Discussion

2632.	There are two mutual perpendicular forces acting on an object. One force acts in the direction of motion of the object and other is perpendicular to the motion. During this interval, the kinetic energy of the body changes from 25 J to 100 J. The work done by the force acting perpendicular to the direction of the object is:
Answer» There are two mutual perpendicular forces acting on an object. One force acts in the direction of motion of the object and other is perpendicular to the motion. During this interval, the kinetic energy of the body changes from 25 J to 100 J. The work done by the force acting perpendicular to the direction of the object is:

Discussion

2633.	Gravitational force on the surface of the moon is only 1/6 as strong as gravitational force on the earth. What is the weight is newtons of a10 kg object on the moon and on the earth..
Answer» Gravitational force on the surface of the moon is only 1/6 as strong as gravitational force on the earth. What is the weight is newtons of a10 kg object on the moon and on the earth..

Discussion

2634.	105.Which of the following is the most prescise device for measuring length ? (a) a vernier callipers with 20 divisions on the sliding scale (b) a screw gauge of pitch 1 mm and 100 divisions on the circular scale (c) an optimal instrument that can measure length to within a wavelength of light Also explain the reason .
Answer» 105.Which of the following is the most prescise device for measuring length ? (a) a vernier callipers with 20 divisions on the sliding scale (b) a screw gauge of pitch 1 mm and 100 divisions on the circular scale (c) an optimal instrument that can measure length to within a wavelength of light Also explain the reason .

Discussion

2635.	An object is dropped from rest at a height of 150 m and simultaneously another object is dropped from rest at a height of 100 m. What is the difference in their heights after 2 s if both the objects drop under the same acceleration? How does the difference in heights vary with time?
Answer» An object is dropped from rest at a height of $150 m$ and simultaneously another object is dropped from rest at a height of $100 m$ . What is the difference in their heights after $2 s$ if both the objects drop under the same acceleration? How does the difference in heights vary with time?

Discussion

2636.	Which of the following are not correct?(i) The basic unit of time is second.(ii) Every object moves with a constant speed.(iii) Distances between two cities are measured in kilometres.(iv) The time period of a given pendulum is constant.(v) The speed of a train is expressed in m/h.
Answer» Which of the following are not correct? (i) The basic unit of time is second. (ii) Every object moves with a constant speed. (iii) Distances between two cities are measured in kilometres. (iv) The time period of a given pendulum is constant. (v) The speed of a train is expressed in m/h.

2636.

Which of the following are not correct?(i) The basic unit of time is second.(ii) Every object moves with a constant speed.(iii) Distances between two cities are measured in kilometres.(iv) The time period of a given pendulum is constant.(v) The speed of a train is expressed in m/h.

Answer» Which of the following are not correct?

(i) The basic unit of time is second.

(ii) Every object moves with a constant speed.

(iii) Distances between two cities are measured in kilometres.

(iv) The time period of a given pendulum is constant.

(v) The speed of a train is expressed in m/h.

Discussion

2637.	How much is the heat energy produced in 10 seconds in an electric iron having resistance 440 Ω, when a potential difference of 220 volt is applied across it?
Answer» How much is the heat energy produced in $10 s e c o n d s$ in an electric iron having resistance $440 Ω$ , when a potential difference of $220 v o l t$ is applied across it?

Discussion

2638.	If two balls made of iron and aluminium of equal volumes are immersed in a liquid,then will they experience equal upthrust?justify the answer?
Answer» If two balls made of iron and aluminium of equal volumes are immersed in a liquid,then will they experience equal upthrust?justify the answer?

Discussion

2639.	A student finds that there are 20 divisions between the 0 mark and 1 V mark of a voltmeter. What is the least count of this voltmeter?(1) 0.50 V(2) 0.02 V(3) 0.2 V(4) 0.05 V
Answer» A student finds that there are 20 divisions between the 0 mark and 1 V mark of a voltmeter. What is the least count of this voltmeter? (1) 0.50 V (2) 0.02 V (3) 0.2 V (4) 0.05 V

Discussion

2640.	Verify that
Answer» Verify that

Discussion

2641.	Conservation of momentum
Answer» Conservation of momentum

Discussion

2642.	What are the laws of Vector?
Answer» What are the laws of Vector?

Discussion

2643.	A nuclear fission is represented by the following reactionU236→X111+Y122+30n1If the binding energies per nucleon of X111, Y122 and U236 are 8.6 MeV,8.5 MeVand 7.6 MeV respectively, then the energy released in the reaction will be
Answer» A nuclear fission is represented by the following reaction $U^{236} \to X^{111} + Y^{122} + 3_{0} n^{1}$ If the binding energies per nucleon of $X^{111},$ $Y^{122}$ and $U^{236}$ are $8.6 MeV, 8.5 MeV$ $and 7.6 MeV$ respectively, then the energy released in the reaction will be

Discussion

2644.	Question 16A gas filled balloon moves up. Is the upward force acting on it larger or smaller than the force of gravity?
Answer» Question 16 A gas filled balloon moves up. Is the upward force acting on it larger or smaller than the force of gravity?

Discussion

2645.	What is the purpose of a barometer ?
Answer» What is the purpose of a barometer ?

Discussion

2646.	Tinku dropped a stone into a very deep well. He hears the sound 6.53 seconds after he dropped the stone. Find the depth of the well. Take acceleration due to gravity, g =10 m/s2 and vsound = 340 m/s.
Answer» Tinku dropped a stone into a very deep well. He hears the sound 6.53 seconds after he dropped the stone. Find the depth of the well. Take acceleration due to gravity, g =10 m/s² and $v_{s o u n d}$ = 340 m/s.

Discussion

2647.	When a train is approaching the stationary observer, the apparent frequency of the whistle observed as {100Hz , while when it has passed away from the observer { with same speed, it is 50Hz . Calculate the frequency of the whistle when the observer moves with the train {(V=330m/s){ (1) 33.3Hz 2) 50Hz 3) 66.6Hz 4) 75Hz
Answer» When a train is approaching the stationary observer, the apparent frequency of the whistle observed as {100Hz , while when it has passed away from the observer { with same speed, it is 50Hz . Calculate the frequency of the whistle when the observer moves with the train {(V=330m/s){ (1) 33.3Hz 2) 50Hz 3) 66.6Hz 4) 75Hz

Discussion

2648.	let suppose that medium 1 is air and medium 2 is water. A light ray a1 refract with r1 angle . now prove the relation between the angle of refraction and speed of the light whether speed of light will decrease with greater angle or increase with greater angle of refraction.
Answer» let suppose that medium 1 is air and medium 2 is water. A light ray a1 refract with r1 angle . now prove the relation between the angle of refraction and speed of the light whether speed of light will decrease with greater angle or increase with greater angle of refraction.

Discussion

2649.	22.A uniform rod of density p is placed in a wide tank,containing a liquid of density po(po>p).the depth of liquid in the tank is half the length of the rod.the rod is in equilibrium with its half the length of the rod with its lower end resting on the bottom of the tank.in this position the rod makes and angle thetha with horizontal,find it. Click here to view details:
Answer» 22.A uniform rod of density p is placed in a wide tank,containing a liquid of density po(po>p).the depth of liquid in the tank is half the length of the rod.the rod is in equilibrium with its half the length of the rod with its lower end resting on the bottom of the tank.in this position the rod makes and angle thetha with horizontal,find it. Click here to view details:

Discussion

2650.	Question 18How is ultrasound used for cleaning?
Answer» Question 18 How is ultrasound used for cleaning?

Discussion

Explore topic-wise InterviewSolutions in .

The ion of an element has 3 positive charges. The mass number of atom of this element is 27 and the number of neutrons is 14. What is the number of electrons in the ion?

what does this mean-when value of relativistic charged particle increases its specific charge remains same. what is relativistic charge??

72.A particle accelerates from rest with constant acceleration a for m seconds . It's velocity at the end of m seconds is v. The displacement of the particle in last 3 seconds is ??

What is the buoyant force experienced by a cube of side 10 cm which is completely immersed in water?(Take g=10 m s−2 and density of water =1000 kg m−3)

An object is kept at a distance of 16 cm from a thin lens and the image formed is real. If the object is kept at a distance of 6 cm from the same lens, the image formed is virtual. If the sizes of the images formed are equal, the focal length of the lens will be :

When iron filings are spread on a piece of paper with a bar magnet kept below , the filings:

Write all the factors that affect fluid friction.

Three forces are acting on a particle of mass m initially in equilibrium. If the first 2 forces (F1and F2) are perpendicular to each other and suddenly the third force F3 is removed, then findacceleration of the particle ?

Choose the most important natural source of energy from the following

A student comments that the speed of object Q is decreasing and the speed of object P is increasing. State whether the comment is correct or incorrect.Justify your answer.

When an electron goes in a straight line the electric flux first increases then decreases. HOW

How to convert watt into Kilowatt and kilowatt into watt

The circuit given below consists of cells with their internal resistance(ii) The equivalent internal resistance of the combination is

Consider an ideal op-amp circuit shown in the figure below:The value of output voltage V0 is equal to

Name the commercial unit of measurement of energy.

What are the steps to solve? The two ends of a train moving with cons†an t acceleration pass a certain point with velocities u and 3u. The velocity with which the middle point of the train passes the same point is

What is the use of particle accelerator?

The distance between a compression and the immediate next rarefaction of a longitudinal wave is: (λ denotes wavelength)

Why Earth is called a unique planet?

How is pressure related to the area over which a force acts?

A glass rod gets electrically charged on rubbing with silk cloth. What's the source of this charge?

30.Derive the expression of velocity of an object thrown as a projectile at any point of its trajectory

(42 The frequency changes by 10% as a sound sourceapproaches a stationary observer with constantspeed V, What would be percentage change inthe frequency as the source recedes the observerwith same speed (V. < V)?(1)10.5%(2) 8.5%(3) 4.5%(4)1.5%

25.An object is projected vertically upward with speed root gR where R is the radius of earth and g is acceleration due to gravity on the surface of earth. Find the maximum height attained by it.

A cube of unknown material supporting a 500 gm mass just sinks in water. When the mass is removed, the cube goes up by 4 cm. Then, the volume of the cube is

The atmosphere is held to the Earth due to:

APS 05 (MeAn object is projected with a velocity of 20 m/smaking an angle of 45^° with horizontal. Theequation for the trajectory is h = Ax - Bx2, whereh is height, x is horizontal distance, A and B areconstants. The ratio of A : B isues(1) 1:5(2) 5:1(3) 1:40(4) 40 1

The scales - vernier callipers, metre scale and screw gauge has the least counts:

the dis†an ce between three consecutive troughs ina wave produced in a string is4cm . if 2.5 wave cycles pass through any point in a second, the wave in the sttring ihas velocity a) 10 cm/s b) 0.16cm/s c) 0.8 cm/s d) 5 cm/s

(3)U.370If mass of earth decreases by 25% and its radius increases by 50%, then acceleration due to gravity at itssurface decreases by nearly670

Gravitational force on the surface of the moon is only 1/6 as strong as gravitational force on the earth. What is the weight is newtons of a10 kg object on the moon and on the earth..

An object is dropped from rest at a height of 150 m and simultaneously another object is dropped from rest at a height of 100 m. What is the difference in their heights after 2 s if both the objects drop under the same acceleration? How does the difference in heights vary with time?

Which of the following are not correct?(i) The basic unit of time is second.(ii) Every object moves with a constant speed.(iii) Distances between two cities are measured in kilometres.(iv) The time period of a given pendulum is constant.(v) The speed of a train is expressed in m/h.

How much is the heat energy produced in 10 seconds in an electric iron having resistance 440 Ω, when a potential difference of 220 volt is applied across it?

If two balls made of iron and aluminium of equal volumes are immersed in a liquid,then will they experience equal upthrust?justify the answer? ​​​

A student finds that there are 20 divisions between the 0 mark and 1 V mark of a voltmeter. What is the least count of this voltmeter?(1) 0.50 V(2) 0.02 V(3) 0.2 V(4) 0.05 V

Verify that

Conservation of momentum

What are the laws of Vector?

A nuclear fission is represented by the following reactionU236→X111+Y122+30n1If the binding energies per nucleon of X111, Y122 and U236 are 8.6 MeV,8.5 MeVand 7.6 MeV respectively, then the energy released in the reaction will be

Question 16A gas filled balloon moves up. Is the upward force acting on it larger or smaller than the force of gravity?

What is the purpose of a barometer ?

Tinku dropped a stone into a very deep well. He hears the sound 6.53 seconds after he dropped the stone. Find the depth of the well. Take acceleration due to gravity, g =10 m/s2 and vsound = 340 m/s.

let suppose that medium 1 is air and medium 2 is water. A light ray a1 refract with r1 angle . now prove the relation between the angle of refraction and speed of the light whether speed of light will decrease with greater angle or increase with greater angle of refraction.

Question 18How is ultrasound used for cleaning?

If two balls made of iron and aluminium of equal volumes are immersed in a liquid,then will they experience equal upthrust?justify the answer?