50278 + Interview Questions in Physics

1.	Why O2 is paramagnetic ?
Answer» Why O₂ is paramagnetic ?

Discussion

2.	Rays from a lens are converging toward a point P as shown in figure. How much thick glass plate having refractive index 1.6 must be located between the lens and point P, so that the image will be formed at P’?
Answer» Rays from a lens are converging toward a point $P$ as shown in figure. How much thick glass plate having refractive index $1.6$ must be located between the lens and point $P$ , so that the image will be formed at $P$ ’?

Discussion

3.	Two rods made of different materials are placed between massive walls (see fig.). The cross-section of the rods is A and their respective lengths are l1and l2. The rods are heated through toC. Find the force with which the rods act on each other if their coefficients of expansion are α1 and α2 and their Young's moduli are E1 and E2. Neglect the deformation of the walls
Answer» Two rods made of different materials are placed between massive walls (see fig.). The cross-section of the rods is A and their respective lengths are $l_{1}$ and $l_{2}$ . The rods are heated through $t^{o}$ C. Find the force with which the rods act on each other if their coefficients of expansion are $α_{1}$ and $α_{2}$ and their Young's moduli are $E_{1}$ and $E_{2}$ . Neglect the deformation of the walls

3.

Two rods made of different materials are placed between massive walls (see fig.). The cross-section of the rods is A and their respective lengths are l1and l2. The rods are heated through toC. Find the force with which the rods act on each other if their coefficients of expansion are α1 and α2 and their Young's moduli are E1 and E2. Neglect the deformation of the walls

Answer»

Two rods made of different materials are placed between massive walls (see fig.). The cross-section of the rods is A and their respective lengths are $l_{1}$ and $l_{2}$ . The rods are heated through $t^{o}$ C. Find the force with which the rods act on each other if their coefficients of expansion are $α_{1}$ and $α_{2}$ and their Young's moduli are $E_{1}$ and $E_{2}$ . Neglect the deformation of the walls

Discussion

4.	A particle is moving on a curve given by y=2 sin2x (x and y are in metres). The x-component of velocity is always 2 m/s. If the particle starts from origin at t=0, then displacement in metres of the particle after π2 s is (answer upto 2 decimal places)
Answer» A particle is moving on a curve given by $y = 2 sin 2 x$ ( $x$ and $y$ are in metres). The x-component of velocity is always $2 m / s$ . If the particle starts from origin at $t = 0$ , then displacement in metres of the particle after $\frac{π}{2} s$ is (answer upto 2 decimal places)

Discussion

5.	An open lift is moving upwards with velocity 10 m/s. It has an upward acceleration of 2 m/s2. A ball is projected upwards with velocity 20 m/s relative to ground. Find the time when ball again meets the lift.
Answer» An open lift is moving upwards with velocity 10 m/s. It has an upward acceleration of 2 m/s $^{2}$ . A ball is projected upwards with velocity 20 m/s relative to ground. Find the time when ball again meets the lift.

Discussion

6.	Find the equivalent resistance for series and parallel system.
Answer» Find the equivalent resistance for series and parallel system.

Discussion

7.	A given object takes n times as much time to slide down a 45° rough incline as it takes to slide down a perfectly smooth 45o incline. The coefficient of kinetic friction between the object and the incline is given by
Answer» A given object takes n times as much time to slide down a 45° rough incline as it takes to slide down a perfectly smooth $45^{o}$ incline. The coefficient of kinetic friction between the object and the incline is given by

Discussion

8.	The correct graph between the kinetic energy of photoelectron and frequency of incident light is:
Answer» The correct graph between the kinetic energy of photoelectron and frequency of incident light is:

Discussion

9.	A pendulum hanging from the ceiling of a railway carriage make an angle of 30∘ with the vertical when it is accelerating. Find the acceleration of the carriage.
Answer» A pendulum hanging from the ceiling of a railway carriage make an angle of $30^{\circ}$ with the vertical when it is accelerating. Find the acceleration of the carriage.

Discussion

10.	A spherical source of power 4 W and frequency 800 Hz is emitting sound waves. The intensity of waves at a distance 200 m is
Answer» A spherical source of power 4 W and frequency 800 Hz is emitting sound waves. The intensity of waves at a distance 200 m is

10.

A spherical source of power 4 W and frequency 800 Hz is emitting sound waves. The intensity of waves at a distance 200 m is

Answer»

A spherical source of power 4 W and frequency 800 Hz is emitting sound waves. The intensity of waves at a distance 200 m is

Discussion

11.	A body is moving from rest under constant acceleration and let S1 be the displacement in the first (p−1) sec and S2 be the displacement in the first p sec. The displacement in (p2−p+1)th sec. will be
Answer» A body is moving from rest under constant acceleration and let $S_{1}$ be the displacement in the first $(p - 1)$ sec and $S_{2}$ be the displacement in the first p sec. The displacement in $(p^{2} - p + 1)^{t h}$ sec. will be

Discussion

12.	An ideal Carnot engine having efficiency η works between temperatures 127°C and −73°C. η1 denotes the efficiency when the temperature of the source increases by 50°C and η2 denotes efficiency when temperature of the sink decreases by 50°C. Then the correct order is
Answer» An ideal Carnot engine having efficiency $η$ works between temperatures $127 ° C$ and $- 73 ° C$ . $η_{1}$ denotes the efficiency when the temperature of the source increases by $50 ° C$ and $η_{2}$ denotes efficiency when temperature of the sink decreases by $50 ° C$ . Then the correct order is

Discussion

13.	The bob of a stationary pendulum is given a sharp hit to impart it a horizontal speed of √3 gl . Find the angle rotated by the string before it becomes slack.
Answer» The bob of a stationary pendulum is given a sharp hit to impart it a horizontal speed of $\sqrt{3 g l}$ . Find the angle rotated by the string before it becomes slack.

Discussion

14.	A steady current is passing through a linear conductor of no uniform cross-section. The net quantity of charge passing through any cross-section per second is
Answer» A steady current is passing through a linear conductor of no uniform cross-section. The net quantity of charge passing through any cross-section per second is

Discussion

15.	Prove that the force acting on a current - carrying wire, joining two fixed points a and b in a uniform magnetic field, is independent of the shape of the wire.
Answer» Prove that the force acting on a current - carrying wire, joining two fixed points a and b in a uniform magnetic field, is independent of the shape of the wire.

Discussion

16.	Calculate the moment of Inertia of an annular disc of inner radius R1 and outer radius R2 about an axis perpendicular to the plane in which the disc lies and passing through O.
Answer» Calculate the moment of Inertia of an annular disc of inner radius $R_{1}$ and outer radius $R_{2}$ about an axis perpendicular to the plane in which the disc lies and passing through O.

16.

Calculate the moment of Inertia of an annular disc of inner radius R1 and outer radius R2 about an axis perpendicular to the plane in which the disc lies and passing through O.

Answer»

Calculate the moment of Inertia of an annular disc of inner radius $R_{1}$ and outer radius $R_{2}$ about an axis perpendicular to the plane in which the disc lies and passing through O.

Discussion

17.	A satellite of the earth is revolving in a circular orbit with a uniform speed v. If the gravitational force suddenly disappears, the satellite will
Answer» A satellite of the earth is revolving in a circular orbit with a uniform speed v. If the gravitational force suddenly disappears, the satellite will

Discussion

18.	In a given circuit, if RMS voltage across resistance and capacitor are 25 V and 30 V, then peak voltage across inductor will be
Answer» In a given circuit, if RMS voltage across resistance and capacitor are 25 V and 30 V, then peak voltage across inductor will be

Discussion

19.	Two cahrged particles ar eplaced at a distance 1.0 cm apart. What is the minimum possible magnitude of the electric force acting on eachcharge?
Answer» Two cahrged particles ar eplaced at a distance 1.0 cm apart. What is the minimum possible magnitude of the electric force acting on eachcharge?

Discussion

20.	Examples for positive, zero and negative work
Answer» Examples for positive, zero and negative work

Discussion

21.	The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation
Answer» The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation

21.

The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation

Answer»

The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation

Discussion

22.	An ideal gas is taken around ABCA as shown in the above P-V diagram. The work done during a cycle is
Answer» An ideal gas is taken around ABCA as shown in the above P-V diagram. The work done during a cycle is

Discussion

23.	A particle is thrown vertically upwards. Its velocity at half of the maximum height is 20 m/s. Then the maximum height attained by it will be: (Take g=10 m/s2)
Answer» A particle is thrown vertically upwards. Its velocity at half of the maximum height is $20 m/s$ . Then the maximum height attained by it will be: (Take $g = 10 {m/s}^{2}$ )

Discussion

24.	In the figure shown below, a 4 kg block is compressed by 2 m. The coefficient of friction between the block and the plane is μ=0.8. Then the frictional force (in N) acting on the block is given by
Answer» In the figure shown below, a $4 k g$ block is compressed by $2 m$ . The coefficient of friction between the block and the plane is $μ = 0.8$ . Then the frictional force (in $N$ ) acting on the block is given by

Discussion

25.	Water is flowing through a channel (lying in a vertical plane) as shown in the figure. Three sections A,B and C are shown. Section B and C have equal areas of cross- section. If PA,PB and PC are the pressures at A,B and C respectively, then
Answer» Water is flowing through a channel (lying in a vertical plane) as shown in the figure. Three sections $A, B$ and $C$ are shown. Section $B$ and $C$ have equal areas of cross- section. If $P_{A}, P_{B}$ and $P_{C}$ are the pressures at $A, B$ and $C$ respectively, then

Discussion

26.	A thick straight wire of length 'π' m is fixed at its midpoint and then bent in the form of a circle. The shift in its centre of mass is
Answer» A thick straight wire of length ' $π$ ' m is fixed at its midpoint and then bent in the form of a circle. The shift in its centre of mass is

Discussion

27.	In Millikan’s oil drop experiment, what is the terminal speed of an uncharged drop of radius 2.0×10–5 m and density 1.2×103kgm–3? Take the viscosity of air at the temperature of the experiment to be 1.8×10–5 Pa s. How much is the viscous force on the drop at that speed? Neglect buoyancy of the drop due to air.
Answer» In Millikan’s oil drop experiment, what is the terminal speed of an uncharged drop of radius $2.0 \times 10^{- 5}$ m and density $1.2 \times 10^{3} k g m^{- 3}$ ? Take the viscosity of air at the temperature of the experiment to be $1.8 \times 10^{- 5}$ Pa s. How much is the viscous force on the drop at that speed? Neglect buoyancy of the drop due to air.

Discussion

28.	Angle θ shown in graph between friction and applied force on a body is
Answer» Angle $θ$ shown in graph between friction and applied force on a body is

Discussion

29.	Four spheres of radii R, 2R, 2R and 3R respectively, are placed such that their respective centres lie at x=2 m, x=6 m, x=10 m and x=20 m respectively. If density of each sphere is the same, then find the x coordinate of COM of the system of spheres.
Answer» Four spheres of radii $R$ , $2 R$ , $2 R$ and $3 R$ respectively, are placed such that their respective centres lie at $x = 2 m$ , $x = 6 m$ , $x = 10 m$ and $x = 20 m$ respectively. If density of each sphere is the same, then find the $x$ coordinate of $COM$ of the system of spheres.

Discussion

30.	A body takes the following path and moves with constant speed. If aA and aB are the magnitude of its radial acceleration at A and B.
Answer» A body takes the following path and moves with constant speed. If $a_{A}$ and $a_{B}$ are the magnitude of its radial acceleration at A and B.

30.

A body takes the following path and moves with constant speed. If aA and aB are the magnitude of its radial acceleration at A and B.

Answer»

A body takes the following path and moves with constant speed. If $a_{A}$ and $a_{B}$ are the magnitude of its radial acceleration at A and B.

Discussion

31.	A power transmission line feeds power at 2200 v with a current of 5 A to a step down transformer with its primary winding having 4000 turns calculate the number of turns and the current in the secondary in order to get output power at 220v
Answer» A power transmission line feeds power at 2200 v with a current of 5 A to a step down transformer with its primary winding having 4000 turns calculate the number of turns and the current in the secondary in order to get output power at 220v

Discussion

32.	If U1,U2,U3 represents the potential energy of mass m moving from A to B along three different paths 1,2 & 3 (as shown in the figure) in the gravitational field, then
Answer» If $U_{1}, U_{2}, U_{3}$ represents the potential energy of mass $m$ moving from A to B along three different paths $1$ , $2$ & $3$ (as shown in the figure) in the gravitational field, then

Discussion

33.	magnetic properties of solids
Answer» magnetic properties of solids

Discussion

34.	In halliday resnick I read a line in current and resistance that "Although an electric current is a steam of moving charges , not all moving charges constitute an electric current. " I want to ask that how do we get to know that these are moving charges which will produce electric current and others will not.
Answer» In halliday resnick I read a line in current and resistance that "Although an electric current is a steam of moving charges , not all moving charges constitute an electric current. " I want to ask that how do we get to know that these are moving charges which will produce electric current and others will not.

34.

In halliday resnick I read a line in current and resistance that "Although an electric current is a steam of moving charges , not all moving charges constitute an electric current. " I want to ask that how do we get to know that these are moving charges which will produce electric current and others will not.

Answer»

In halliday resnick I read a line in current and resistance that

"Although an electric current is a steam of moving charges , not all moving charges constitute an electric current. " I want to ask that how do we get to know that these are moving charges which will produce electric current and others will not.

Discussion

35.	A force F=10 N is acting on pulley of mass M=2 kg and radius R=1 m as shown in the figure. If pulley is rotating with constant angular velocity ω=4 rad/s. Find the power delivered by the force F to the pulley.
Answer» A force $F = 10 N$ is acting on pulley of mass $M = 2 kg$ and radius $R = 1 m$ as shown in the figure. If pulley is rotating with constant angular velocity $ω = 4 rad/s$ . Find the power delivered by the force $F$ to the pulley.

Discussion

36.	Two bullets are fired with horizontal velocities of 50m/s and 100m/s from two guns at a height of 19.6m . After how much time will the bullets strike the ground and which one will strike first?
Answer» Two bullets are fired with horizontal velocities of 50m/s and 100m/s from two guns at a height of 19.6m . After how much time will the bullets strike the ground and which one will strike first?

Discussion

37.	How many times does the electron go around the first Bohr's orbit of hydrogen in one second?
Answer» How many times does the electron go around the first Bohr's orbit of hydrogen in one second?

Discussion

38.	A square hole of side length l is made at a depth of y and a circular hole is made at a depth of 4y from the surface of water in a water tank kept on a horizontal surface. If equal amount of water comes out of the vessel through the holes per second then the radius of the circular hole is equal to (l<<y)
Answer» A square hole of side length l is made at a depth of y and a circular hole is made at a depth of 4y from the surface of water in a water tank kept on a horizontal surface. If equal amount of water comes out of the vessel through the holes per second then the radius of the circular hole is equal to (l<<y)

Discussion

39.	A circular race track of radius 300 m is banked at an angle of 15 degrees. If the coefficient of friction between the wheels of a race car and the road is 0.2, what is the optimum speed of the race car to avoid wear and tear on its tires ?
Answer» A circular race track of radius 300 m is banked at an angle of 15 degrees. If the coefficient of friction between the wheels of a race car and the road is 0.2, what is the optimum speed of the race car to avoid wear and tear on its tires ?

Discussion

40.	Paramagnetic substances are:
Answer» Paramagnetic substances are:

Discussion

41.	If you are pushing the wall then the wall will also push you back according to 3rd law.. so which is action and which is reaction.
Answer» If you are pushing the wall then the wall will also push you back according to 3rd law.. so which is action and which is reaction.

Discussion

42.	If the net force acting on the system of particles is zero, then which of the following may vary
Answer» If the net force acting on the system of particles is zero, then which of the following may vary

Discussion

43.	When a mass m is hung from the lower of a spring of negligible mass, an extension x is produced in the spring. The mass is set into vertical oscillations.The time period of oscillation is
Answer» When a mass m is hung from the lower of a spring of negligible mass, an extension x is produced in the spring. The mass is set into vertical oscillations.The time period of oscillation is

Discussion

44.	Change in no. of magnetic field lines primarily induces:
Answer» Change in no. of magnetic field lines primarily induces:

Discussion

45.	A hoop of radius and mass m rotating with an angular velocity omega is placed on a rough horizontal surface.The initial velocity of the centre of the hoop is zero.What will be the velocity of the centre of the hoop when it ceases to slip?
Answer» A hoop of radius and mass m rotating with an angular velocity omega is placed on a rough horizontal surface.The initial velocity of the centre of the hoop is zero.What will be the velocity of the centre of the hoop when it ceases to slip?

Discussion

46.	The plate resistance of a triode is 8kΩ and the transconductance is 2.5 millimho. (a) If the plate voltage is increased by 48 V, and the grid voltage is kept constant what will be the increase in the plate current? (b) With plate voltage kept constant at this increased value, how much should the grid voltage be decreased in order to bring the plate current bac to its initial value?
Answer» The plate resistance of a triode is $8 k Ω$ and the transconductance is 2.5 millimho. (a) If the plate voltage is increased by 48 V, and the grid voltage is kept constant what will be the increase in the plate current? (b) With plate voltage kept constant at this increased value, how much should the grid voltage be decreased in order to bring the plate current bac to its initial value?

Discussion

47.	A convex lens produces a real image m times the size of the object. What will be the distance of the object from the lens
Answer» A convex lens produces a real image m times the size of the object. What will be the distance of the object from the lens

Discussion

48.	Using B=μ0H find the ratio E0H0 for a plane electromagnetic wave propagating through vacuum. Show that it has the dimensions of electric resistance. this ratio is a universal constant called the impedance of free space.
Answer» Using $B = μ_{0} H$ find the ratio $\frac{E_{0}}{H_{0}}$ for a plane electromagnetic wave propagating through vacuum. Show that it has the dimensions of electric resistance. this ratio is a universal constant called the impedance of free space.

Discussion

49.	The density of water at 0∘ C is 0.998 g cm−3 and at 4∘ C is 1.000 g cm−3. Calculate the average coefficient of volume expansion of water in the temperature range 0 to 4C.
Answer» The density of water at $0^{\circ} C$ is 0.998 g $c m^{- 3}$ and at $4^{\circ} C$ is 1.000 g $c m^{- 3}$ . Calculate the average coefficient of volume expansion of water in the temperature range 0 to $4^{C}$ .

Discussion

50.	A charge q is placed at the centre of the open end of cylindrical vessel. The flux of the electric field through the surface of the vessel is
Answer» A charge q is placed at the centre of the open end of cylindrical vessel. The flux of the electric field through the surface of the vessel is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Why O2 is paramagnetic ?

Rays from a lens are converging toward a point P as shown in figure. How much thick glass plate having refractive index 1.6 must be located between the lens and point P, so that the image will be formed at P’?

A particle is moving on a curve given by y=2 sin2x (x and y are in metres). The x-component of velocity is always 2 m/s. If the particle starts from origin at t=0, then displacement in metres of the particle after π2 s is (answer upto 2 decimal places)

An open lift is moving upwards with velocity 10 m/s. It has an upward acceleration of 2 m/s2. A ball is projected upwards with velocity 20 m/s relative to ground. Find the time when ball again meets the lift.

Find the equivalent resistance for series and parallel system.

A given object takes n times as much time to slide down a 45° rough incline as it takes to slide down a perfectly smooth 45o incline. The coefficient of kinetic friction between the object and the incline is given by

The correct graph between the kinetic energy of photoelectron and frequency of incident light is:

A pendulum hanging from the ceiling of a railway carriage make an angle of 30∘ with the vertical when it is accelerating. Find the acceleration of the carriage.

A spherical source of power 4 W and frequency 800 Hz is emitting sound waves. The intensity of waves at a distance 200 m is

A body is moving from rest under constant acceleration and let S1 be the displacement in the first (p−1) sec and S2 be the displacement in the first p sec. The displacement in (p2−p+1)th sec. will be

An ideal Carnot engine having efficiency η works between temperatures 127°C and −73°C. η1 denotes the efficiency when the temperature of the source increases by 50°C and η2 denotes efficiency when temperature of the sink decreases by 50°C. Then the correct order is

The bob of a stationary pendulum is given a sharp hit to impart it a horizontal speed of √3 gl . Find the angle rotated by the string before it becomes slack.

A steady current is passing through a linear conductor of no uniform cross-section. The net quantity of charge passing through any cross-section per second is

Prove that the force acting on a current - carrying wire, joining two fixed points a and b in a uniform magnetic field, is independent of the shape of the wire.

Calculate the moment of Inertia of an annular disc of inner radius R1 and outer radius R2 about an axis perpendicular to the plane in which the disc lies and passing through O.

A satellite of the earth is revolving in a circular orbit with a uniform speed v. If the gravitational force suddenly disappears, the satellite will

In a given circuit, if RMS voltage across resistance and capacitor are 25 V and 30 V, then peak voltage across inductor will be

Two cahrged particles ar eplaced at a distance 1.0 cm apart. What is the minimum possible magnitude of the electric force acting on eachcharge?

Examples for positive, zero and negative work

The spring balance A reads 2 kg with a block m suspended from it. A balance B reads 5 kg when a beaker filled with liquid is put on the pan of the balance. The two balances are now so arranged that the hanging mass is inside the liquid as shown in figure. In this situation

An ideal gas is taken around ABCA as shown in the above P-V diagram. The work done during a cycle is

A particle is thrown vertically upwards. Its velocity at half of the maximum height is 20 m/s. Then the maximum height attained by it will be: (Take g=10 m/s2)

In the figure shown below, a 4 kg block is compressed by 2 m. The coefficient of friction between the block and the plane is μ=0.8. Then the frictional force (in N) acting on the block is given by

Water is flowing through a channel (lying in a vertical plane) as shown in the figure. Three sections A,B and C are shown. Section B and C have equal areas of cross- section. If PA,PB and PC are the pressures at A,B and C respectively, then

A thick straight wire of length 'π' m is fixed at its midpoint and then bent in the form of a circle. The shift in its centre of mass is

Angle θ shown in graph between friction and applied force on a body is

Four spheres of radii R, 2R, 2R and 3R respectively, are placed such that their respective centres lie at x=2 m, x=6 m, x=10 m and x=20 m respectively. If density of each sphere is the same, then find the x coordinate of COM of the system of spheres.

A body takes the following path and moves with constant speed. If aA and aB are the magnitude of its radial acceleration at A and B.

A power transmission line feeds power at 2200 v with a current of 5 A to a step down transformer with its primary winding having 4000 turns calculate the number of turns and the current in the secondary in order to get output power at 220v

If U1,U2,U3 represents the potential energy of mass m moving from A to B along three different paths 1,2 &amp; 3 (as shown in the figure) in the gravitational field, then

magnetic properties of solids

A force F=10 N is acting on pulley of mass M=2 kg and radius R=1 m as shown in the figure. If pulley is rotating with constant angular velocity ω=4 rad/s. Find the power delivered by the force F to the pulley.

Two bullets are fired with horizontal velocities of 50m/s and 100m/s from two guns at a height of 19.6m . After how much time will the bullets strike the ground and which one will strike first?

How many times does the electron go around the first Bohr's orbit of hydrogen in one second?

A circular race track of radius 300 m is banked at an angle of 15 degrees. If the coefficient of friction between the wheels of a race car and the road is 0.2, what is the optimum speed of the race car to avoid wear and tear on its tires ?

Paramagnetic substances are:

If you are pushing the wall then the wall will also push you back according to 3rd law.. so which is action and which is reaction.

If the net force acting on the system of particles is zero, then which of the following may vary

When a mass m is hung from the lower of a spring of negligible mass, an extension x is produced in the spring. The mass is set into vertical oscillations.The time period of oscillation is

Change in no. of magnetic field lines primarily induces:

A hoop of radius and mass m rotating with an angular velocity omega is placed on a rough horizontal surface.The initial velocity of the centre of the hoop is zero.What will be the velocity of the centre of the hoop when it ceases to slip?

A convex lens produces a real image m times the size of the object. What will be the distance of the object from the lens

Using B=μ0H find the ratio E0H0 for a plane electromagnetic wave propagating through vacuum. Show that it has the dimensions of electric resistance. this ratio is a universal constant called the impedance of free space.

The density of water at 0∘ C is 0.998 g cm−3 and at 4∘ C is 1.000 g cm−3. Calculate the average coefficient of volume expansion of water in the temperature range 0 to 4C.

A charge q is placed at the centre of the open end of cylindrical vessel. The flux of the electric field through the surface of the vessel is

If U1,U2,U3 represents the potential energy of mass m moving from A to B along three different paths 1,2 & 3 (as shown in the figure) in the gravitational field, then