50278 + Interview Questions in Physics

1.	At a height of 0.4 m from the ground, the velocity of a projectile in vector form is→v=(6^i+2^j) m/s. The angle of projection is (g=10 m/s2)
Answer» At a height of $0.4 m$ from the ground, the velocity of a projectile in vector form is $\to v = (6^i + 2^j) m / s .$ The angle of projection is $(g = 10 m / s^{2})$

Discussion

2.	A massless wire 2 m in length suspended vertically stretches by 10 mm when mass of 10 kg is attached to the lower end. The elastic potential energy gained by the wire is (Take g=10 m/s2)
Answer» A massless wire $2 m$ in length suspended vertically stretches by $10 mm$ when mass of $10 kg$ is attached to the lower end. The elastic potential energy gained by the wire is (Take $g = 10 {m/s}^{2}$ )

Discussion

3.	For given combination of capacitor where each capacitance is C Equivalent capacitance of the system is
Answer» For given combination of capacitor where each capacitance is C Equivalent capacitance of the system is

Discussion

4.	Mass of upper block and lower block kept over the table is 2 kg and 1 kg respectively and coefficient of friction between the blocks is 0.1. Table surface is smooth. The maximum mass m for which all the three blocks move with same acceleration is (g=10 m/s2)
Answer» Mass of upper block and lower block kept over the table is $2 k g$ and $1 k g$ respectively and coefficient of friction between the blocks is $0.1$ . Table surface is smooth. The maximum mass $m$ for which all the three blocks move with same acceleration is $(g = 10 m / s^{2})$

Discussion

5.	A 20 kg wagon originally at rest, is pushed with a force of 7 N for 1.5 s, then with a force of 5 N for 1.7 s and then with a force of 10 N for 3 s. Find the final velocity of the cart.
Answer» A $20 kg$ wagon originally at rest, is pushed with a force of $7 N$ for $1.5 s$ , then with a force of $5 N$ for $1.7 s$ and then with a force of $10 N$ for $3 s$ . Find the final velocity of the cart.

Discussion

6.	sphere of 4 cm radius is suspended within a hollow sphere of radius 6cm the inner sphere is charged to a potential 3S you when the outer sphere is earthed the charge on the inner sphere is
Answer» sphere of 4 cm radius is suspended within a hollow sphere of radius 6cm the inner sphere is charged to a potential 3S you when the outer sphere is earthed the charge on the inner sphere is

Discussion

7.	Write a Condition in which instantaneous velocity and average velocity are same.
Answer» Write a Condition in which instantaneous velocity and average velocity are same.

Discussion

8.	A charged particle moves through a magnetic field in a direction perpendicular to it , then which of the following quantities remains unchanged?
Answer» A charged particle moves through a magnetic field in a direction perpendicular to it , then which of the following quantities remains unchanged?

Discussion

9.	Force of interaction between two co axial short electric dipoles whose centres are R distance apart varies as
Answer» Force of interaction between two co axial short electric dipoles whose centres are R distance apart varies as

Discussion

10.	A cubical block of wood of edge 3 cm floats in water. The lower surface of the cube just touches the free end of a vertical spring fixed at the bottom of the pot. Find the maximum weight that can be put on the block without wetting it. (Take density of wood =800 kg/m3, spring constant of the spring =50 N/m and g=10 m/s2.)
Answer» A cubical block of wood of edge $3 cm$ floats in water. The lower surface of the cube just touches the free end of a vertical spring fixed at the bottom of the pot. Find the maximum weight that can be put on the block without wetting it. (Take density of wood $= 800 {kg/m}^{3}$ , spring constant of the spring $= 50 N/m$ and $g = 10 {m/s}^{2}$ .)

Discussion

11.	Two points of differences between interference and diffraction
Answer» Two points of differences between interference and diffraction

Discussion

12.	A shell of mass 'm' is projected with velocity V at an angle 60o to the horizontal. When it reaches the maximum height, then its angular momentum with respect to point of projection
Answer» A shell of mass 'm' is projected with velocity V at an angle $60^{o}$ to the horizontal. When it reaches the maximum height, then its angular momentum with respect to point of projection

Discussion

13.	The galvanometer shown in the figure has a resistance 50 Ω and full-scale deflection current 1 mA. What are the the resistances R1,R2 and R3 required to convert it into ammeter having ranges as indicated?
Answer» The galvanometer shown in the figure has a resistance $50 Ω$ and full-scale deflection current 1 mA. What are the the resistances $R_{1}, R_{2}$ and $R_{3}$ required to convert it into ammeter having ranges as indicated?

Discussion

14.	Consider a swimmer with velocity Vs in still water. He now tries to cross a river flowing due north with velocity Vr=V0(1−x2a2), where x=−a and x=+a are banks of river. X-axis is towards east. Displacement of man towards the north, if he crosses the river in minimum time is
Answer» Consider a swimmer with velocity $V_{s}$ in still water. He now tries to cross a river flowing due north with velocity $V_{r} = V_{0} (1 - \frac{x^{2}}{a^{2}})$ , where $x = - a$ and $x = + a$ are banks of river. X-axis is towards east. Displacement of man towards the north, if he crosses the river in minimum time is

Discussion

15.	Recall the term used to describe the possible energies that electrons in an atom can have.
Answer» Recall the term used to describe the possible energies that electrons in an atom can have.

Discussion

16.	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

17.	What is Young's modulus of a material ?
Answer» What is Young's modulus of a material ?

Discussion

18.	The velocity of water in a river is 18 kmh−1 near the surface. If the river is 5 m deep, then the shearing stress between the surface layer and the bottom layer is: (Given - coefficient of viscosity of water, η=10−3 Pa.s)
Answer» The velocity of water in a river is $18 {kmh}^{- 1}$ near the surface. If the river is $5 m$ deep, then the shearing stress between the surface layer and the bottom layer is: (Given - coefficient of viscosity of water, $η = 10^{- 3} Pa.s$ )

Discussion

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

Discussion

20.	In a carrier frequency of 100kHz and a modulating frequency of 5kHz. What is the bandwidth of AM transmission
Answer» In a carrier frequency of 100kHz and a modulating frequency of 5kHz. What is the bandwidth of AM transmission

Discussion

21.	Can I put an object in an orbit around me assuming that I am present in empty space with negligible gravitational influences around me. If not, how do we calculate the minimum mass that an object should possess to create an orbit for another body around itself?
Answer» Can I put an object in an orbit around me assuming that I am present in empty space with negligible gravitational influences around me. If not, how do we calculate the minimum mass that an object should possess to create an orbit for another body around itself?

Discussion

22.	Difference between center of mass and center of gravity
Answer» Difference between center of mass and center of gravity

Discussion

23.	Two bodies of metal are mounted on glass stands. Their surface area is equal but one is a sphere and other is pear shaped. Both are given the same amount of charge. Which one will lose its charge first?
Answer» Two bodies of metal are mounted on glass stands. Their surface area is equal but one is a sphere and other is pear shaped. Both are given the same amount of charge. Which one will lose its charge first?

Discussion

24.	The amplitude of S.H.M at resonance is _______ in the ideal case of zero damping.
Answer» The amplitude of S.H.M at resonance is _______ in the ideal case of zero damping.

Discussion

25.	A 1500-kg car moving on a flat, horizontal road negotiates a curve. If the radius of the curve is 20.0 m and the coefficient of static friction between the tires and dry pavement is 0.50, find the maximum speed the car can have so that it still makes the turn successfully.
Answer» A 1500-kg car moving on a flat, horizontal road negotiates a curve. If the radius of the curve is 20.0 m and the coefficient of static friction between the tires and dry pavement is 0.50, find the maximum speed the car can have so that it still makes the turn successfully.

Discussion

26.	A block of 5 kg mass rests on a horizontal floor. The action of the block on the floor is
Answer» A block of 5 kg mass rests on a horizontal floor. The action of the block on the floor is

Discussion

27.	A sphere of radius r is kept on a concave mirror of radius of curvature R. The arrangement is kept on a horizontal table (the surface of concave mirror is frictionless and sliding not rolling). If the sphere is displaced from its equilibrium position and left, then it executes S.H.M. The period of oscillation will be
Answer» A sphere of radius r is kept on a concave mirror of radius of curvature R. The arrangement is kept on a horizontal table (the surface of concave mirror is frictionless and sliding not rolling). If the sphere is displaced from its equilibrium position and left, then it executes S.H.M. The period of oscillation will be

Discussion

28.	If a water drop is kept between two glass plates, then its shape is
Answer» If a water drop is kept between two glass plates, then its shape is

28.

If a water drop is kept between two glass plates, then its shape is

Answer»

If a water drop is kept between two glass plates, then its shape is

Discussion

29.	Power of a water pump is 2 kW. If g=10m/sec2 , the amount of water it can raise in one minute to a height of 10 m is
Answer» Power of a water pump is 2 kW. If $g = 10 m / s e c^{2}$ , the amount of water it can raise in one minute to a height of 10 m is

Discussion

30.	Consider the situation shown in figure. Find the maximum angle θ for which the light suffers total internal reflection at the vertical surface.
Answer» Consider the situation shown in figure. Find the maximum angle $θ$ for which the light suffers total internal reflection at the vertical surface.

Discussion

31.	What amount of work is done in increasing the length of a wire through unity?
Answer» What amount of work is done in increasing the length of a wire through unity?

Discussion

32.	Each of the three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wires A and B has cross-sectional area 0.005 cm^{2} and Young modulus 2 \times 10^{11} N~m^{2}. Neglect friction. Find the longitudinal strain developed in wire B. Take g=10m s−2.
Answer» Each of the three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wires A and B has cross-sectional area 0.005 cm^{2} and Young modulus 2 \times 10^{11} N~m^{2}. Neglect friction. Find the longitudinal strain developed in wire B. Take $g = 10 m s^{- 2} .$

Discussion

33.	Why do the transformers not follow the ohm's law?
Answer» Why do the transformers not follow the ohm's law?

Discussion

34.	A body is dropped from a height of 39.2 m. After it crosses the half distance, the acceleration due to gravity comes to an end. Then the body will hit the ground with a velocity of (Take g=9.8 ms−2)
Answer» A body is dropped from a height of $39.2 m$ . After it crosses the half distance, the acceleration due to gravity comes to an end. Then the body will hit the ground with a velocity of $($ Take $g = 9.8 {ms}^{- 2})$

Discussion

35.	Two lenses with powers; 2D & -4D are kept together. What is the effective focal length of the combination?
Answer» Two lenses with powers; 2D & -4D are kept together. What is the effective focal length of the combination?

Discussion

36.	In the circuit shown below the cells E1 and E2 have emf’s 4 V and 8 V and internal resistance 0.5 ohm and 1 ohm respectively. Then the potential difference across cell E1 and E2 will be
Answer» In the circuit shown below the cells $E_{1}$ and $E_{2}$ have emf’s 4 V and 8 V and internal resistance 0.5 ohm and 1 ohm respectively. Then the potential difference across cell $E_{1}$ and $E_{2}$ will be

Discussion

37.	c1c0+2.c2c1+3.c3c2+...+n.cnn1=
Answer» $\frac{c_{1}}{c_{0}} + 2. \frac{c_{2}}{c_{1}} + 3. \frac{c_{3}}{c_{2}} + . . . + n . \frac{c_{n}}{n_{1}}$ =

Discussion

38.	Three weights W, 2W and 2W are connected to identical springs suspended form rigid lkhorizontal rod. The assembly of the rod and the weights fall freely. The positions of the weights from the rod are such that
Answer» Three weights W, 2W and 2W are connected to identical springs suspended form rigid lkhorizontal rod. The assembly of the rod and the weights fall freely. The positions of the weights from the rod are such that

Discussion

39.	A particle is subjected to two simple harmonic motions given by x1=2.0 sin(100 π t) and x2=2.0 sin(120 π t+π/3), where x is in centimeter and t in second. Find the displacement of the particle at (a) t=0.0125, (b) t=0.025.
Answer» A particle is subjected to two simple harmonic motions given by $x_{1} = 2.0 s i n (100 π t)$ and $x_{2} = 2.0 s i n (120 π t + π / 3)$ , where x is in centimeter and t in second. Find the displacement of the particle at (a) $t = 0.0125,$ (b) $t = 0.025.$

39.

A particle is subjected to two simple harmonic motions given by x1=2.0 sin(100 π t) and x2=2.0 sin(120 π t+π/3), where x is in centimeter and t in second. Find the displacement of the particle at (a) t=0.0125, (b) t=0.025.

Answer»

A particle is subjected to two simple harmonic motions given by

$x_{1} = 2.0 s i n (100 π t)$ and $x_{2} = 2.0 s i n (120 π t + π / 3)$ ,

where x is in centimeter and t in second. Find the displacement of the particle at (a) $t = 0.0125,$ (b) $t = 0.025.$

Discussion

40.	A charge q is circulating in an orbit of radius r making n revolutions per second. The magnetic field produced at the center of the circle inTesla is
Answer» A charge q is circulating in an orbit of radius r making n revolutions per second. The magnetic field produced at the center of the circle inTesla is

Discussion

41.	Why do we need dearrangement if we have both permutation and combination?
Answer» Why do we need dearrangement if we have both permutation and combination?

Discussion

42.	A vector →A makes an angle of 200 and →B makes an angle of 1100 with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the resultant.
Answer» A vector $\to A$ makes an angle of $20^{0}$ and $\to B$ makes an angle of $110^{0}$ with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the resultant.

Discussion

43.	A long circular tube of length 10 m and radius 0.3 m carries a current I along its curved surface as shown. A wire-loop of resistance 0.005 ohm and of radius 0.1 m is placed inside the tube with its axis coinciding with the axis of the tube. The current varies as I=I0cos(300t), where I0 is constant. If the magnetic moment of the loop is Nμ0I0sin(300t), then find N
Answer» A long circular tube of length 10 m and radius 0.3 m carries a current I along its curved surface as shown. A wire-loop of resistance 0.005 ohm and of radius 0.1 m is placed inside the tube with its axis coinciding with the axis of the tube. The current varies as $I = I_{0} c o s (300 t),$ where $I_{0}$ is constant. If the magnetic moment of the loop is $N μ_{0} I_{0} s i n (300 t),$ then find N

Discussion

44.	A block of mass m is pulled along a horizontal surface by applying a force at an angle θ with the horizontal. If the block travels with a uniform velocity and has a displacement d and the coefficient of friction is μ. then the work done by the applied force is
Answer» A block of mass m is pulled along a horizontal surface by applying a force at an angle $θ$ with the horizontal. If the block travels with a uniform velocity and has a displacement d and the coefficient of friction is $μ$ . then the work done by the applied force is

Discussion

45.	Moment of Inertia of a thin uniform rod rotating about the perpendicular axis passing through its centre is I. If the same rod is bent into a ring and its moment of inertia about its diameter is I’, then the ratio II′ is
Answer» Moment of Inertia of a thin uniform rod rotating about the perpendicular axis passing through its centre is I. If the same rod is bent into a ring and its moment of inertia about its diameter is I’, then the ratio $\frac{I}{I^{'}}$ is

Discussion

46.	Water is flowing continuously from a tap having an internal diameter 8×10−3m. The water velocity as it leaves the tap is 0.4 ms−1. The diameter of the water stream at a distance 2×10−1m below the tap is close to
Answer» Water is flowing continuously from a tap having an internal diameter $8 \times 10^{- 3} m$ . The water velocity as it leaves the tap is $0.4 m s^{- 1}$ . The diameter of the water stream at a distance $2 \times 10^{- 1} m$ below the tap is close to

Discussion

47.	A thin symmetrical double convex lens of power P is cut into three parts (A,B,C), as shown in the figure. Power of A is:
Answer» A thin symmetrical double convex lens of power $P$ is cut into three parts $(A, B, C)$ , as shown in the figure. Power of $A$ is:

Discussion

48.	A thermally insulated chamber of volume 2v0 is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure P0 and temperature T0 and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be x0 in equilibrium.
Answer» A thermally insulated chamber of volume $2 v_{0}$ is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure $P_{0}$ and temperature $T_{0}$ and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be $x_{0}$ in equilibrium.

48.

A thermally insulated chamber of volume 2v0 is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure P0 and temperature T0 and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be x0 in equilibrium.

Answer»

A thermally insulated chamber of volume $2 v_{0}$ is divided by a frictionless piston of area ‘S’ into two equal parts A and B. Part ‘A’ has an ideal gas at pressure $P_{0}$ and temperature $T_{0}$ and in part B there is vacuum. A massless spring of force constant k is connected with piston and the wall of the container as shown. Initially spring is unstretched. Gas in chamber A is allowed to expand. Consider the compression in spring to be $x_{0}$ in equilibrium.

Discussion

49.	A metallic sphere having radius 0.08m and mass m = 10 kg is heated to a temperature of 227∘ Cand suspended inside a box whose walls are at a temperature of 27∘ C. The maximum rate at which its temperature will fall is Take e=1, σ=5.8×10−8 Wm−2 K−4 and specific heat of the metal S=90 cal/kg/k; J=4.2 J/cal)
Answer» A metallic sphere having radius 0.08m and mass m = 10 kg is heated to a temperature of $227^{\circ} C$ and suspended inside a box whose walls are at a temperature of $27^{\circ} C$ . The maximum rate at which its temperature will fall is Take $e = 1, σ = 5.8 \times 10^{- 8} W m^{- 2} K^{- 4}$ and specific heat of the metal $S = 90 c a l / k g / k; J = 4.2 J / c a l)$

Discussion

50.	The K.E of mole of an ideal gas is E=32 RT. Then Cp will be
Answer» The K.E of mole of an ideal gas is $E = \frac{3}{2} RT$ . Then $C_{p}$ will be

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

At a height of 0.4 m from the ground, the velocity of a projectile in vector form is→v=(6^i+2^j) m/s. The angle of projection is (g=10 m/s2)

A massless wire 2 m in length suspended vertically stretches by 10 mm when mass of 10 kg is attached to the lower end. The elastic potential energy gained by the wire is (Take g=10 m/s2)

For given combination of capacitor where each capacitance is C Equivalent capacitance of the system is

Mass of upper block and lower block kept over the table is 2 kg and 1 kg respectively and coefficient of friction between the blocks is 0.1. Table surface is smooth. The maximum mass m for which all the three blocks move with same acceleration is (g=10 m/s2)

A 20 kg wagon originally at rest, is pushed with a force of 7 N for 1.5 s, then with a force of 5 N for 1.7 s and then with a force of 10 N for 3 s. Find the final velocity of the cart.

sphere of 4 cm radius is suspended within a hollow sphere of radius 6cm the inner sphere is charged to a potential 3S you when the outer sphere is earthed the charge on the inner sphere is

Write a Condition in which instantaneous velocity and average velocity are same.

A charged particle moves through a magnetic field in a direction perpendicular to it , then which of the following quantities remains unchanged?

Force of interaction between two co axial short electric dipoles whose centres are R distance apart varies as

Two points of differences between interference and diffraction

A shell of mass 'm' is projected with velocity V at an angle 60o to the horizontal. When it reaches the maximum height, then its angular momentum with respect to point of projection

The galvanometer shown in the figure has a resistance 50 Ω and full-scale deflection current 1 mA. What are the the resistances R1,R2 and R3 required to convert it into ammeter having ranges as indicated?

Consider a swimmer with velocity Vs in still water. He now tries to cross a river flowing due north with velocity Vr=V0(1−x2a2), where x=−a and x=+a are banks of river. X-axis is towards east. Displacement of man towards the north, if he crosses the river in minimum time is

Recall the term used to describe the possible energies that electrons in an atom can have.

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

What is Young's modulus of a material ?

The velocity of water in a river is 18 kmh−1 near the surface. If the river is 5 m deep, then the shearing stress between the surface layer and the bottom layer is: (Given - coefficient of viscosity of water, η=10−3 Pa.s)

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

In a carrier frequency of 100kHz and a modulating frequency of 5kHz. What is the bandwidth of AM transmission

Can I put an object in an orbit around me assuming that I am present in empty space with negligible gravitational influences around me. If not, how do we calculate the minimum mass that an object should possess to create an orbit for another body around itself?

Difference between center of mass and center of gravity

Two bodies of metal are mounted on glass stands. Their surface area is equal but one is a sphere and other is pear shaped. Both are given the same amount of charge. Which one will lose its charge first?

The amplitude of S.H.M at resonance is _______ in the ideal case of zero damping.

A 1500-kg car moving on a flat, horizontal road negotiates a curve. If the radius of the curve is 20.0 m and the coefficient of static friction between the tires and dry pavement is 0.50, find the maximum speed the car can have so that it still makes the turn successfully.

A block of 5 kg mass rests on a horizontal floor. The action of the block on the floor is

If a water drop is kept between two glass plates, then its shape is

Power of a water pump is 2 kW. If g=10m/sec2 , the amount of water it can raise in one minute to a height of 10 m is

Consider the situation shown in figure. Find the maximum angle θ for which the light suffers total internal reflection at the vertical surface.

What amount of work is done in increasing the length of a wire through unity?

Each of the three blocks P, Q and R shown in figure has a mass of 3 kg. Each of the wires A and B has cross-sectional area 0.005 cm^{2} and Young modulus 2 \times 10^{11} N~m^{2}. Neglect friction. Find the longitudinal strain developed in wire B. Take g=10m s−2.

Why do the transformers not follow the ohm's law?

A body is dropped from a height of 39.2 m. After it crosses the half distance, the acceleration due to gravity comes to an end. Then the body will hit the ground with a velocity of (Take g=9.8 ms−2)

Two lenses with powers; 2D &amp; -4D are kept together. What is the effective focal length of the combination?

In the circuit shown below the cells E1 and E2 have emf’s 4 V and 8 V and internal resistance 0.5 ohm and 1 ohm respectively. Then the potential difference across cell E1 and E2 will be

c1c0+2.c2c1+3.c3c2+...+n.cnn1=

Three weights W, 2W and 2W are connected to identical springs suspended form rigid lkhorizontal rod. The assembly of the rod and the weights fall freely. The positions of the weights from the rod are such that

A particle is subjected to two simple harmonic motions given by x1=2.0 sin(100 π t) and x2=2.0 sin(120 π t+π/3), where x is in centimeter and t in second. Find the displacement of the particle at (a) t=0.0125, (b) t=0.025.

A charge q is circulating in an orbit of radius r making n revolutions per second. The magnetic field produced at the center of the circle inTesla is

Why do we need dearrangement if we have both permutation and combination?

A vector →A makes an angle of 200 and →B makes an angle of 1100 with the X-axis. The magnitudes of these vectors are 3 m and 4 m respectively. Find the resultant.

A block of mass m is pulled along a horizontal surface by applying a force at an angle θ with the horizontal. If the block travels with a uniform velocity and has a displacement d and the coefficient of friction is μ. then the work done by the applied force is

Moment of Inertia of a thin uniform rod rotating about the perpendicular axis passing through its centre is I. If the same rod is bent into a ring and its moment of inertia about its diameter is I’, then the ratio II′ is

Water is flowing continuously from a tap having an internal diameter 8×10−3m. The water velocity as it leaves the tap is 0.4 ms−1. The diameter of the water stream at a distance 2×10−1m below the tap is close to

A thin symmetrical double convex lens of power P is cut into three parts (A,B,C), as shown in the figure. Power of A is:

The K.E of mole of an ideal gas is E=32 RT. Then Cp will be

Two lenses with powers; 2D & -4D are kept together. What is the effective focal length of the combination?