13232 + Interview Questions in Physics Page 25 InterviewSolution

1201.	To what height should a box of mass 150 kg be lifted, so that its potential energy may become 7350 joules ? (g = 9.8 m/s2).
Answer» To what height should a box of mass 150 kg be lifted, so that its potential energy may become 7350 joules ? (g = 9.8 $m / s^{2}$ ).

Discussion

1202.	ntThe displacement of a particle at an instant is given to ben nty = rsin[t θ]n ntWhere r = amplitude, is angular velocity and θ is angle, the velocity and acceleration of particle isn ntn
Answer» ntThe displacement of a particle at an instant is given to ben nty = rsin[t θ]n ntWhere r = amplitude, is angular velocity and θ is angle, the velocity and acceleration of particle isn ntn

Discussion

1203.	What is a virtual image? Give one situation where a virtual image is formed.
Answer» What is a virtual image? Give one situation where a virtual image is formed.

Discussion

1204.	Identify the case in which the static friction is acting.
Answer» Identify the case in which the static friction is acting.

Discussion

1205.	Question 3Electrical resistivity of a given metallic wire depends upon(a) its length(b) its thickness(c) its shape(d) nature of the material
Answer» Question 3 Electrical resistivity of a given metallic wire depends upon (a) its length (b) its thickness (c) its shape (d) nature of the material

Discussion

1206.	A solid weight 50 gf in the air and 44 gf when completely immersed in water. Calculate i) The upthrust (ii) Volume of the solid and (iii) The relative density of the solid
Answer» A solid weight 50 gf in the air and 44 gf when completely immersed in water. Calculate i) The upthrust (ii) Volume of the solid and (iii) The relative density of the solid

Discussion

1207.	Check the following to see whether each one of them is inversely proportional or not. The number of workers on a job and the time to complete the job. The time taken for a journey and the distance travelled at a uniform speed.
Answer» Check the following to see whether each one of them is inversely proportional or not. The number of workers on a job and the time to complete the job. The time taken for a journey and the distance travelled at a uniform speed.

Discussion

1208.	What are the Vector Laws in physic
Answer» What are the Vector Laws in physic

Discussion

1209.	particle falling from rest under gravity covers a height H in 5 seconds. If it continues falling then next distance H will be covered in appr oximately(2) 3 s2 S(4) 5 s(3) 4 s
Answer» particle falling from rest under gravity covers a height H in 5 seconds. If it continues falling then next distance H will be covered in appr oximately(2) 3 s2 S(4) 5 s(3) 4 s

Discussion

1210.	What is Newton third law
Answer» What is Newton third law

Discussion

1211.	The resistance of a metal wire of length 1 m is 25 Ω at 20∘ Celsius. If the diameter of the wire is 0.3 mm, then the resistivity of the wire at that temperature is
Answer» The resistance of a metal wire of length $1 m$ is $25 Ω$ at $20^{\circ}$ Celsius. If the diameter of the wire is $0.3 m m,$ then the resistivity of the wire at that temperature is

Discussion

1212.	The force due to the magnetic field on a current carrying conductor is _______ to the magnetic field and_________ to the current.
Answer» The force due to the magnetic field on a current carrying conductor is _______ to the magnetic field and_________ to the current.

Discussion

1213.	What is the relation between the weight of an object on the moon and that on the earth?
Answer» What is the relation between the weight of an object on the moon and that on the earth?

Discussion

1214.	Question 71(ii)The following graph shows the journey made by two cyclists, one from town A to B and the other from town B to A.Was cyclist II cycling faster or slower after the rest?
Answer» Question 71(ii) The following graph shows the journey made by two cyclists, one from town A to B and the other from town B to A. Was cyclist II cycling faster or slower after the rest?

Discussion

1215.	A body falling from high minarent travels 40 m in the last 2sec of its fall to ground.find the hight of minarebt in meter
Answer» A body falling from high minarent travels 40 m in the last 2sec of its fall to ground.find the hight of minarebt in meter

Discussion

1216.	Name the two characteristics of sound which differentiate two sounds from each other.
Answer» Name the two characteristics of sound which differentiate two sounds from each other.

Discussion

1217.	Fill in the blanks:(1) A solid is completely immersed in a liquid. The force exerted by the liquid on the solid will be in vertically ………….. direction.(2) When an object sinks into the liquid, the density of object is ………….. than density of the liquid.(3) The …………… on unit surface area is called pressure.(4) The buoyant force is greater if density is ………….. .(5) The SI unit of pressure is ……………. .
Answer» Fill in the blanks: (1) A solid is completely immersed in a liquid. The force exerted by the liquid on the solid will be in vertically ………….. direction. (2) When an object sinks into the liquid, the density of object is ………….. than density of the liquid. (3) The …………… on unit surface area is called pressure. (4) The buoyant force is greater if density is ………….. . (5) The SI unit of pressure is ……………. .

1217.

Fill in the blanks:(1) A solid is completely immersed in a liquid. The force exerted by the liquid on the solid will be in vertically ………….. direction.(2) When an object sinks into the liquid, the density of object is ………….. than density of the liquid.(3) The …………… on unit surface area is called pressure.(4) The buoyant force is greater if density is ………….. .(5) The SI unit of pressure is ……………. .

Answer»

Fill in the blanks:

(1) A solid is completely immersed in a liquid. The force exerted by the liquid on the solid will be in vertically ………….. direction.

(2) When an object sinks into the liquid, the density of object is ………….. than density of the liquid.

(3) The …………… on unit surface area is called pressure.

(4) The buoyant force is greater if density is ………….. .

(5) The SI unit of pressure is ……………. .

Discussion

1218.	Question 3The kinetic energy of an object of mass, m moving with a velocity of 5ms−1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?
Answer» Question 3 The kinetic energy of an object of mass, m moving with a velocity of $5 m s^{- 1}$ is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

Discussion

1219.	A plane sound wave is travelling in a medium. In reference to a frame A, its equation is: y=a cos [ωt−kx].With reference to a frame B, moving with a constant velocity v in the direction of propagation of the wave, equation of the wave cannot be
Answer» A plane sound wave is travelling in a medium. In reference to a frame A, its equation is: $y = a c o s [ω t - k x]$ . With reference to a frame B, moving with a constant velocity v in the direction of propagation of the wave, equation of the wave cannot be

Discussion

1220.	A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases? [3 MARKS]
Answer» A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 $Ω$ resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases? [3 MARKS]

Discussion

1221.	The equation of the progressive wave, where t is the time in second, x is the distance in metre isy = Acos240 (t-x/12) The phase difference (in Sl units) between two positions 0.5 m apart is(1) 40 (3) 10 (2) 20 (4) 5
Answer» The equation of the progressive wave, where t is the time in second, x is the distance in metre isy = Acos240 (t-x/12) The phase difference (in Sl units) between two positions 0.5 m apart is(1) 40 (3) 10 (2) 20 (4) 5

Discussion

1222.	Why? G=gm1m2r2
Answer» Why? $G = g m^{1} \frac{m^{2}}{r^{2}}$

Discussion

1223.	For columns (square cross section having side 100 mm) resists a buckling load of P. Now, the columns glued together to act as a single column. The percentage increase in buckling load is300
Answer» For columns (square cross section having side 100 mm) resists a buckling load of P. Now, the columns glued together to act as a single column. The percentage increase in buckling load is 300

Discussion

1224.	What would be the refractive index of the core of an optical fiber if the critical angle is 60∘ and the refractive index of the cladding is √3 ? (Cladding is the outer covering in the optical fiber.) Refer the figure given below:-
Answer» What would be the refractive index of the core of an optical fiber if the critical angle is $60^{\circ}$ and the refractive index of the cladding is $\sqrt{3}$ ? (Cladding is the outer covering in the optical fiber.) Refer the figure given below:-

Discussion

1225.	A particle is projected with speed u at angle θ with horizontal from ground if it is at same height from the ground at time t1 and t2 then its average velocity in time interval t1 to t2 is
Answer» A particle is projected with speed u at angle θ with horizontal from ground if it is at same height from the ground at time t1 and t2 then its average velocity in time interval t1 to t2 is

Discussion

1226.	Most of the earth's carbon is found in ___.
Answer» Most of the earth's carbon is found in ___.

Discussion

1227.	If a charge of 750 C flows through the cross-section of a conducting wire in 5 minutes, what is the value of the current that flows through the wire?
Answer» If a charge of $750 C$ flows through the cross-section of a conducting wire in $5 minutes$ , what is the value of the current that flows through the wire?

Discussion

1228.	A body falling from rest covered distances S1,S2 and S3 in first,second,third seconds of its fall. Calculate the ratio of S1,S2 and S3 respectively.
Answer» A body falling from rest covered distances S1,S2 and S3 in first,second,third seconds of its fall. Calculate the ratio of S1,S2 and S3 respectively.

Discussion

1229.	a ball is thrown vertically upward with a given velocity v such that it rises for T seconds (T>1).the dis†an ce traversed by the ball during the last second of ascent is given by
Answer» a ball is thrown vertically upward with a given velocity v such that it rises for T seconds (T>1).the dis†an ce traversed by the ball during the last second of ascent is given by

Discussion

1230.	A wheel mounted on a stationary axle starts from rest and accelerates with angular acceleration α = 2 + 0.4t rad / s2. Find the angular velocity of wheel after 4 sec of its start.
Answer» A wheel mounted on a stationary axle starts from rest and accelerates with angular acceleration α = 2 + 0.4t rad / s². Find the angular velocity of wheel after 4 sec of its start.

Discussion

1231.	If displacement is directly proportional to square of time then motion isA uniform accelerationB increasing accelerationC decreasing acceleration
Answer» If displacement is directly proportional to square of time then motion is A uniform acceleration B increasing acceleration C decreasing acceleration

Discussion

1232.	Which of the following will does not allow sound propagation?
Answer» Which of the following will does not allow sound propagation?

Discussion

1233.	When an object is placed at a distance of 25 cm from a mirror, the magnification of the real image formed is m1. When the object is moved 15 cm away with respect to the earlier position along the principal axis, magnification becomes m2. If m1×m2=4, the focal length of the mirror in cm is P×10. Then, find the value of P
Answer» When an object is placed at a distance of $25 cm$ from a mirror, the magnification of the real image formed is $m_{1}$ . When the object is moved $15 cm$ away with respect to the earlier position along the principal axis, magnification becomes $m_{2}$ . If $m_{1} \times m_{2} = 4$ , the focal length of the mirror in $cm$ is $P \times 10$ . Then, find the value of $P$

Discussion

1234.	The electro static force on a small sphere of charge o.4ųc due to another small sphere of charge-0.8ųc in air is 0.2N. a) what is the distance between them. b) What is force on the second sphere due to the first
Answer» The electro static force on a small sphere of charge o.4ųc due to another small sphere of charge-0.8ųc in air is 0.2N. a) what is the distance between them. b) What is force on the second sphere due to the first

Discussion

1235.	Work Energy Theore A body of mass m accelerates uniformly from to velocity v, in time interval T,. The instantantaneous power delivered to the body as a function of time t is : 2mv mv 2) T T. 2 mv1 T. 2 T.
Answer» Work Energy Theore A body of mass m accelerates uniformly from to velocity v, in time interval T,. The instantantaneous power delivered to the body as a function of time t is : 2mv mv 2) T T. 2 mv1 T. 2 T.

Discussion

1236.	3. A square loop of side 6 cm carries a current of 30 A. Calculate the magnitude of magnetic field B at a point P lying on the axis of the loop and a distance 7 cm from centre of the loop.
Answer» 3. A square loop of side 6 cm carries a current of 30 A. Calculate the magnitude of magnetic field B at a point P lying on the axis of the loop and a distance 7 cm from centre of the loop.

Discussion

1237.	Why is the barometric height used as a unit to express the atmosphric pressure ?
Answer» Why is the barometric height used as a unit to express the atmosphric pressure ?

Discussion

1238.	the displacement x and time of travel for a particle moving on a straight line is t=\surd(x^2-1) then its acceleration at time is
Answer» the displacement x and time of travel for a particle moving on a straight line is t=\surd(x^2-1) then its acceleration at time is

Discussion

1239.	Let A={1, 2, 3, 4 ,5, 5}. Insert the appropriate symbol ∈ or ∉ on the blank space: (i) 5.....A (ii) 8.....A (iii) 0.....A (iv) 4.....A (v) 2.....A (vi) 10.....A
Answer» Let $A = {1, 2, 3, 4, 5, 5} .$ Insert the appropriate symbol $\in$ or $\notin$ on the blank space: $(i) 5..... A (i i) 8..... A (i i i) 0..... A$ $(i v) 4..... A (v) 2..... A (v i) 10..... A$

1239.

Let A={1, 2, 3, 4 ,5, 5}. Insert the appropriate symbol ∈ or ∉ on the blank space: (i) 5.....A (ii) 8.....A (iii) 0.....A (iv) 4.....A (v) 2.....A (vi) 10.....A

Answer»

Let $A = {1, 2, 3, 4, 5, 5} .$ Insert the appropriate symbol $\in$ or $\notin$ on the blank space:

$(i) 5..... A (i i) 8..... A (i i i) 0..... A$

$(i v) 4..... A (v) 2..... A (v i) 10..... A$

Discussion

1240.	22.If Bohrs's quantisation postulate is a basic law of nature, it should be equally valid for the case of planetary motion also, why then do we never speak of quantisation of orbits of planets around the sun ?
Answer» 22.If Bohrs's quantisation postulate is a basic law of nature, it should be equally valid for the case of planetary motion also, why then do we never speak of quantisation of orbits of planets around the sun ?

Discussion

1241.	Law of gravity says that between two point masses there exists a force of gravity. But that is only for spheres and shells. So is there any separate law for other objects (except for spheres and shells) or the same law holds good. If it does explain how?
Answer» Law of gravity says that between two point masses there exists a force of gravity. But that is only for spheres and shells. So is there any separate law for other objects (except for spheres and shells) or the same law holds good. If it does explain how?

Discussion

1242.	A stone is dropped from a cliff. Find its speed after the stone has fallen from 100 m. (Take g=9.8 ms−2).
Answer» A stone is dropped from a cliff. Find its speed after the stone has fallen from 100 m. (Take $g = 9.8 m s^{- 2}$ ).

Discussion

1243.	For a wide rectangular channel using Manning's formula, the differential equation of gradually varied flow (with the usual notations) is given by
Answer» For a wide rectangular channel using Manning's formula, the differential equation of gradually varied flow (with the usual notations) is given by

Discussion

1244.	The velocity of a freely falling body, starting at rest and after one second is roughly equal to ___.
Answer» The velocity of a freely falling body, starting at rest and after one second is roughly equal to ___.

Discussion

1245.	12. Effect of pressure on melting point of ice?
Answer» 12. Effect of pressure on melting point of ice?

Discussion

1246.	An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?
Answer» An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

Discussion

1247.	In above 3 figures, the arrows indicate the direction of force and magnitude of the force is written above/below the arrows. Which box is experiencing balanced forces?
Answer» In above 3 figures, the arrows indicate the direction of force and magnitude of the force is written above/below the arrows. Which box is experiencing balanced forces?

1247.

In above 3 figures, the arrows indicate the direction of force and magnitude of the force is written above/below the arrows. Which box is experiencing balanced forces?

Answer»

In above 3 figures, the arrows indicate the direction of force and magnitude of the force is written above/below the arrows.

Which box is experiencing balanced forces?

Discussion

1248.	(a) Explain by an example what is meant by potential energy. Write down the expression for gravitational potential energy of a body of mass m placed at a height h above the surface of the earth. (b) What is the difference between potential energy and kinetic energy? (c) A ball of mass 0.5 kg slows down from a speed of 5 m/s to that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.
Answer» (a) Explain by an example what is meant by potential energy. Write down the expression for gravitational potential energy of a body of mass m placed at a height h above the surface of the earth. (b) What is the difference between potential energy and kinetic energy? (c) A ball of mass 0.5 kg slows down from a speed of 5 m/s to that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.

1248.

(a) Explain by an example what is meant by potential energy. Write down the expression for gravitational potential energy of a body of mass m placed at a height h above the surface of the earth. (b) What is the difference between potential energy and kinetic energy? (c) A ball of mass 0.5 kg slows down from a speed of 5 m/s to that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.

Answer»

(a) Explain by an example what is meant by potential energy. Write down the expression for gravitational potential energy of a body of mass m placed at a height h above the surface of the earth.

(b) What is the difference between potential energy and kinetic energy?

(c) A ball of mass 0.5 kg slows down from a speed of 5 m/s to that of 3 m/s. Calculate the change in kinetic energy of the ball. State your answer giving proper units.

Discussion

1249.	what are static crashes which can be heard in radio??
Answer» what are static crashes which can be heard in radio??

Discussion

1250.	If the moon attracts the earth then why does not the earth falll towards the moon?
Answer» If the moon attracts the earth then why does not the earth falll towards the moon?

Discussion

Explore topic-wise InterviewSolutions in .

To what height should a box of mass 150 kg be lifted, so that its potential energy may become 7350 joules ? (g = 9.8 m/s2).

ntThe displacement of a particle at an instant is given to ben nty = rsin[t θ]n ntWhere r = amplitude, is angular velocity and θ is angle, the velocity and acceleration of particle isn ntn

What is a virtual image? Give one situation where a virtual image is formed.

Identify the case in which the static friction is acting.

Question 3Electrical resistivity of a given metallic wire depends upon(a) its length(b) its thickness(c) its shape(d) nature of the material

A solid weight 50 gf in the air and 44 gf when completely immersed in water. Calculate i) The upthrust (ii) Volume of the solid and (iii) The relative density of the solid

Check the following to see whether each one of them is inversely proportional or not. The number of workers on a job and the time to complete the job. The time taken for a journey and the distance travelled at a uniform speed.

What are the Vector Laws in physic

particle falling from rest under gravity covers a height H in 5 seconds. If it continues falling then next distance H will be covered in appr oximately(2) 3 s2 S(4) 5 s(3) 4 s

What is Newton third law

The resistance of a metal wire of length 1 m is 25 Ω at 20∘ Celsius. If the diameter of the wire is 0.3 mm, then the resistivity of the wire at that temperature is

The force due to the magnetic field on a current carrying conductor is _______ to the magnetic field and_________ to the current.

What is the relation between the weight of an object on the moon and that on the earth?

Question 71(ii)The following graph shows the journey made by two cyclists, one from town A to B and the other from town B to A.Was cyclist II cycling faster or slower after the rest?

A body falling from high minarent travels 40 m in the last 2sec of its fall to ground.find the hight of minarebt in meter

Name the two characteristics of sound which differentiate two sounds from each other.

Question 3The kinetic energy of an object of mass, m moving with a velocity of 5ms−1 is 25 J. What will be its kinetic energy when its velocity is doubled? What will be its kinetic energy when its velocity is increased three times?

A plane sound wave is travelling in a medium. In reference to a frame A, its equation is: y=a cos [ωt−kx].With reference to a frame B, moving with a constant velocity v in the direction of propagation of the wave, equation of the wave cannot be

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases? [3 MARKS]

The equation of the progressive wave, where t is the time in second, x is the distance in metre isy = Acos240 (t-x/12) The phase difference (in Sl units) between two positions 0.5 m apart is(1) 40 (3) 10 (2) 20 (4) 5

Why? G=gm1m2r2

For columns (square cross section having side 100 mm) resists a buckling load of P. Now, the columns glued together to act as a single column. The percentage increase in buckling load is300

What would be the refractive index of the core of an optical fiber if the critical angle is 60∘ and the refractive index of the cladding is √3 ? (Cladding is the outer covering in the optical fiber.) Refer the figure given below:-

A particle is projected with speed u at angle θ with horizontal from ground if it is at same height from the ground at time t1 and t2 then its average velocity in time interval t1 to t2 is

Most of the earth's carbon is found in ___.

If a charge of 750 C flows through the cross-section of a conducting wire in 5 minutes, what is the value of the current that flows through the wire?

A body falling from rest covered distances S1,S2 and S3 in first,second,third seconds of its fall. Calculate the ratio of S1,S2 and S3 respectively.

a ball is thrown vertically upward with a given velocity v such that it rises for T seconds (T>1).the dis†an ce traversed by the ball during the last second of ascent is given by

A wheel mounted on a stationary axle starts from rest and accelerates with angular acceleration α = 2 + 0.4t rad / s2. Find the angular velocity of wheel after 4 sec of its start.

If displacement is directly proportional to square of time then motion isA uniform accelerationB increasing accelerationC decreasing acceleration

Which of the following will does not allow sound propagation?

The electro static force on a small sphere of charge o.4ųc due to another small sphere of charge-0.8ųc in air is 0.2N. a) what is the distance between them. b) What is force on the second sphere due to the first

Work Energy Theore A body of mass m accelerates uniformly from to velocity v, in time interval T,. The instantantaneous power delivered to the body as a function of time t is : 2mv mv 2) T T. 2 mv1 T. 2 T.

3. A square loop of side 6 cm carries a current of 30 A. Calculate the magnitude of magnetic field B at a point P lying on the axis of the loop and a distance 7 cm from centre of the loop.

Why is the barometric height used as a unit to express the atmosphric pressure ?

the displacement x and time of travel for a particle moving on a straight line is t=\surd(x^2-1) then its acceleration at time is

Let A={1, 2, 3, 4 ,5, 5}. Insert the appropriate symbol ∈ or ∉ on the blank space: (i) 5.....A (ii) 8.....A (iii) 0.....A (iv) 4.....A (v) 2.....A (vi) 10.....A

22.If Bohrs's quantisation postulate is a basic law of nature, it should be equally valid for the case of planetary motion also, why then do we never speak of quantisation of orbits of planets around the sun ?

Law of gravity says that between two point masses there exists a force of gravity. But that is only for spheres and shells. So is there any separate law for other objects (except for spheres and shells) or the same law holds good. If it does explain how?

A stone is dropped from a cliff. Find its speed after the stone has fallen from 100 m. (Take g=9.8 ms−2).

For a wide rectangular channel using Manning's formula, the differential equation of gradually varied flow (with the usual notations) is given by

The velocity of a freely falling body, starting at rest and after one second is roughly equal to ___.

12. Effect of pressure on melting point of ice?

An engine pumps water continuously through a hose. Water leaves the hose with a velocity v and m is the mass per unit length of the water jet. What is the rate at which kinetic energy is imparted to water?

In above 3 figures, the arrows indicate the direction of force and magnitude of the force is written above/below the arrows. Which box is experiencing balanced forces?

what are static crashes which can be heard in radio??

If the moon attracts the earth then why does not the earth falll towards the moon?

The force due to the magnetic field on a current carrying conductor is _ to the magnetic field and___ to the current.