50278 + Interview Questions in Physics

1.	46.Two inclined planes forming angles 30^° and 45^° are hinged together .A weightless pulley is attached to the hinge.Two bodies A and B each of weight 1kg are linked by rope passing over the pulley.1. Find acceleration of system and tension of rope neglecting the friction. 2.Solve the problem if the coefficient of friction between the two bodies are 0.1
Answer» 46.Two inclined planes forming angles 30^° and 45^° are hinged together .A weightless pulley is attached to the hinge.Two bodies A and B each of weight 1kg are linked by rope passing over the pulley.1. Find acceleration of system and tension of rope neglecting the friction. 2.Solve the problem if the coefficient of friction between the two bodies are 0.1

Discussion

2.	The ration of rotational to kinetic energy for a hollow sphere in pure rolling motio
Answer» The ration of rotational to kinetic energy for a hollow sphere in pure rolling motio

Discussion

3.	The rate of change of position with respect to time is called ___
Answer» The rate of change of position with respect to time is called ___

Discussion

4.	The surface tension of water is 72 dyne/cm. Convert it in SI unit.
Answer» The surface tension of water is 72 dyne/cm. Convert it in SI unit.

Discussion

5.	At time t = 0 sec a particle starts moving along the x-axis. If its kinetic energy increases uniformly with time ‘t’, the net force acting on it must be proportional to
Answer» At time t = 0 sec a particle starts moving along the x-axis. If its kinetic energy increases uniformly with time ‘t’, the net force acting on it must be proportional to

Discussion

6.	(a) Six lead-acid type of secondary cells each of emf 2.0 V and internalresistance 0.015 W are joined in series to provide a supply to aresistance of 8.5 W. What are the current drawn from the supplyand its terminal voltage? (b) A secondary cell after long use has an emf of 1.9 V and a largeinternal resistance of 380 W. What maximum current can be drawnfrom the cell? Could the cell drive the starting motor of a car?
Answer» (a) Six lead-acid type of secondary cells each of emf 2.0 V and internalresistance 0.015 W are joined in series to provide a supply to aresistance of 8.5 W. What are the current drawn from the supplyand its terminal voltage? (b) A secondary cell after long use has an emf of 1.9 V and a largeinternal resistance of 380 W. What maximum current can be drawnfrom the cell? Could the cell drive the starting motor of a car?

Discussion

7.	At 298 K, the enthalpy of fusion of a solid (X) is 2.8 KJ mol−1 and the enthalpy of vaporisation of the liquid (X) is 98.2 KJ mol−1. The enthalpy of sublimation of the substance (X) in KJ mol−1 is . (in nearest integer)
Answer» At $298 K$ , the enthalpy of fusion of a solid $(X)$ is $2.8 {KJ mol}^{- 1}$ and the enthalpy of vaporisation of the liquid $(X)$ is $98.2 K J {mol}^{- 1}$ . The enthalpy of sublimation of the substance $(X)$ in $K J {mol}^{- 1}$ is . (in nearest integer)

Discussion

8.	Glycerine flows steadily through a horizontal tube of length 1.5 m and radius 1.0 cm. If the amount of glycerine collected per second at one end is 4.0 × 10¯³ kg s–¯¹, what is the pressure difference between the two ends of the tube ? (Density of glycerine = 1.3 × 103 kg m¯³ and viscosity of glycerine = 0.83 Pa s). [You may also like to check if the assumption of laminar flow in the tube is correct].
Answer» Glycerine flows steadily through a horizontal tube of length 1.5 m and radius 1.0 cm. If the amount of glycerine collected per second at one end is 4.0 × 10¯³ kg s–¯¹, what is the pressure difference between the two ends of the tube ? (Density of glycerine = 1.3 × 103 kg m¯³ and viscosity of glycerine = 0.83 Pa s). [You may also like to check if the assumption of laminar flow in the tube is correct].

Discussion

9.	Find avector in the direction of vector whichhas magnitude 8 units.
Answer» Find a vector in the direction of vector which has magnitude 8 units.

Discussion

10.	Two bodies of masses 3 kg and 6 kg possess kinetic energies of 6 J and 10 J respectively. What is the ratio of their linear momentum?
Answer» Two bodies of masses $3 kg$ and $6 kg$ possess kinetic energies of $6 J$ and $10 J$ respectively. What is the ratio of their linear momentum?

Discussion

11.	92. For a simple pendulum, graph between velocity (v) and displacement (x) is?
Answer» 92. For a simple pendulum, graph between velocity (v) and displacement (x) is?

Discussion

12.	A deutron and an alpha particle are placed in an electric field. The force acting on them are F1 and F2 and their acceleration are a1 and a2 respectively then 1.F1=F2 2.F1>F2 3.a1=a2 4.a1 not equal to a2
Answer» A deutron and an alpha particle are placed in an electric field. The force acting on them are F1 and F2 and their acceleration are a1 and a2 respectively then 1.F1=F2 2.F1>F2 3.a1=a2 4.a1 not equal to a2

Discussion

13.	Theacceleration due to gravity on the surface of moon is 1.7 ms–2.What is the time period of a simple pendulum on the surface of moonif its time period on the surface of earth is 3.5 s? (gon the surface of earth is 9.8 ms–2)
Answer» The acceleration due to gravity on the surface of moon is 1.7 ms^–2. What is the time period of a simple pendulum on the surface of moon if its time period on the surface of earth is 3.5 s? (g on the surface of earth is 9.8 ms^–2)

Discussion

14.	A bob is hanging over a pulley inside a car through a string. The second end of the string is in the hand of a person standing in the car. The car is moving with constant acceleration 'a' directed horizontally as shown in figure. Other end of the string is pulled with constant acceleration 'a' vertically (with respect to train). The tension in the string is equal to
Answer» A bob is hanging over a pulley inside a car through a string. The second end of the string is in the hand of a person standing in the car. The car is moving with constant acceleration 'a' directed horizontally as shown in figure. Other end of the string is pulled with constant acceleration 'a' vertically (with respect to train). The tension in the string is equal to

14.

A bob is hanging over a pulley inside a car through a string. The second end of the string is in the hand of a person standing in the car. The car is moving with constant acceleration 'a' directed horizontally as shown in figure. Other end of the string is pulled with constant acceleration 'a' vertically (with respect to train). The tension in the string is equal to

Answer»

A bob is hanging over a pulley inside a car through a string. The second end of the string is in the hand of a person standing in the car. The car is moving with constant acceleration 'a' directed horizontally as shown in figure. Other end of the string is pulled with constant acceleration 'a' vertically (with respect to train). The tension in the string is equal to

Discussion

15.	The area bounded by y=xe\|x\|, x− axis and \|x\|=1 is (in sq. units)
Answer» The area bounded by $y = x e^{\| x \|}$ , $x -$ axis and $\| x \| = 1$ is (in sq. units)

Discussion

16.	Given the speed-time graph of a golf ball shot from ground at t = 0. What will be the time of flight?
Answer» Given the speed-time graph of a golf ball shot from ground at t = 0. What will be the time of flight?

16.

Given the speed-time graph of a golf ball shot from ground at t = 0. What will be the time of flight?

Answer»

Given the speed-time graph of a golf ball shot from ground at t = 0.
What will be the time of flight?

Discussion

17.	The potential difference between the surface of charged sphere (radius R) and at the distance 3R from the surface of sphere is V. The electric field at the distance which is equal to radius R from the surface will be:
Answer» The potential difference between the surface of charged sphere (radius $R$ ) and at the distance $3 R$ from the surface of sphere is $V$ . The electric field at the distance which is equal to radius $R$ from the surface will be:

Discussion

18.	Question 24 Suppose the distance between earth and sun becomes half of its present distance. What is likely to happen to life?
Answer» Question 24 Suppose the distance between earth and sun becomes half of its present distance. What is likely to happen to life?

Discussion

19.	In order to determine the equivalent resistance of two resistors R1 and R2 connected in series, a student made this circuit for his experiment.The only statement which is true for this circuit is that it gives:(1) incorrect readings for current I as well as for potential difference V(2) correct reading for current I but incorrect reading for potential difference V(3) incorrect reading for current I but correct reading for potential difference V(4) correct readings for both current I and potential difference V
Answer» In order to determine the equivalent resistance of two resistors R₁ and R₂ connected in series, a student made this circuit for his experiment. The only statement which is true for this circuit is that it gives: (1) incorrect readings for current I as well as for potential difference V (2) correct reading for current I but incorrect reading for potential difference V (3) incorrect reading for current I but correct reading for potential difference V (4) correct readings for both current I and potential difference V

Discussion

20.	3218. In an inductor, the current I varies with time t as5A16 (A/s) t. If induced emf in the inductoris 5 mV, the self inductance of the inductor is(1) 3.75% 10-3H(2) 3.75% 10-4H(3) 3.125% 10-3H(4) 3.125% 10-4HSX
Answer» 3218. In an inductor, the current I varies with time t as5A16 (A/s) t. If induced emf in the inductoris 5 mV, the self inductance of the inductor is(1) 3.75% 10-3H(2) 3.75% 10-4H(3) 3.125% 10-3H(4) 3.125% 10-4HSX

Discussion

21.	An enclosure of volume V contains a mixture of 8 g of oxygen, 14 g of nitrogen and 22 g of carbon- dioxide at absolute temperature T. The pressure of the mixture of gases is (R is universal gas constant)
Answer» An enclosure of volume $V$ contains a mixture of $8 g$ of oxygen, $14 g$ of nitrogen and $22 g$ of carbon- dioxide at absolute temperature $T$ . The pressure of the mixture of gases is ( $R$ is universal gas constant)

Discussion

22.	A particle is projected downwards from point 'A' with initial velocity 5 m/s at an angle θ=37oC with the vertical. A strong horizontal wind gives the particle a constant horizontal acceleration of 6 m/s2 in the x - direction. If the particle strikes the ground directly under its released position, the height 'h' of point A (in m) is (answer upto two decimal places). The downward acceleration is taken as g=10 m/s2 , take (sin37°=3/5, cos37°=4/5)
Answer» A particle is projected downwards from point 'A' with initial velocity $5 m / s$ at an angle $θ = 37^{o} C$ with the vertical. A strong horizontal wind gives the particle a constant horizontal acceleration of $6 m / s^{2}$ in the x - direction. If the particle strikes the ground directly under its released position, the height 'h' of point A (in $m$ ) is (answer upto two decimal places). The downward acceleration is taken as $g = 10 m / s^{2}$ , take (sin37°=3/5, cos37°=4/5)

Discussion

23.	Two small balls having the same mass and charge are located on the same vertical at height H1 and H2 are thrown in the same direction along the horizontal at the same velocity V. the first ball touches the ground at l distance from the initial vertical at what height will the second ball be at that this instant
Answer» Two small balls having the same mass and charge are located on the same vertical at height H1 and H2 are thrown in the same direction along the horizontal at the same velocity V. the first ball touches the ground at l distance from the initial vertical at what height will the second ball be at that this instant

Discussion

24.	why if the kinetic engy of a sytem is zero impkies(implies) its line momentum is also zsero(zero)?
Answer» why if the kinetic engy of a sytem is zero impkies(implies) its line momentum is also zsero(zero)?

Discussion

25.	The velocity-time graph of a particle in straight line motion is shown in figure. The particle starts its motion from origin. Find the average acceleration from 2 s to 6 s.
Answer» The velocity-time graph of a particle in straight line motion is shown in figure. The particle starts its motion from origin. Find the average acceleration from $2 s to 6 s$ .

Discussion

26.	A certain region of a soap bubble reflects red light of wavelength λ=650 nm. What is the minimum thickness that this region of the soap bubble could have? Take the index of the refraction of the soap film to be 1.41.
Answer» A certain region of a soap bubble reflects red light of wavelength $λ = 650 n m$ . What is the minimum thickness that this region of the soap bubble could have? Take the index of the refraction of the soap film to be 1.41.

Discussion

27.	The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).
Answer» The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).

Discussion

28.	The decrease in the value of g (wrt earth's surface) on going to a height R2 above the earth’s surface will be?
Answer» The decrease in the value of $g$ (wrt earth's surface) on going to a height $\frac{R}{2}$ above the earth’s surface will be?

Discussion

29.	A cylinder with a movable piston contains 3 moles of hydrogen at standard temperature and pressure. The walls of the cylinder are made of a heat insulator, and the piston is insulated by having a pile of sand on it. By what factor does the pressure of the gas increase if the gas is compressed to half its original volume ?
Answer» A cylinder with a movable piston contains 3 moles of hydrogen at standard temperature and pressure. The walls of the cylinder are made of a heat insulator, and the piston is insulated by having a pile of sand on it. By what factor does the pressure of the gas increase if the gas is compressed to half its original volume ?

Discussion

30.	A sphere of radius R and charge Q is plaan imaginary sphere of radius 2R whose centrecoincides with the given sphere. The flux related toimaginary sphere isplaced inside(22Q4Q(3) E(4) E,
Answer» A sphere of radius R and charge Q is plaan imaginary sphere of radius 2R whose centrecoincides with the given sphere. The flux related toimaginary sphere isplaced inside(22Q4Q(3) E(4) E,

Discussion

31.	Magnetic moment due to the motion of the electron in nth energy state of hydrogen atom is proportional to
Answer» Magnetic moment due to the motion of the electron in $n^{t h}$ energy state of hydrogen atom is proportional to

Discussion

32.	11.A DISC IN WHICH SEVERAL GROOVES ARE CUT ALONG THE CHORD DRAWN FROM A POINT A, IS ARRANGED IN A VERTICLE PLANE , SEVERAL PARTICLES START SLIPPING FROM A ALONG GROOVES SIMULTANEOUSLY . ASSUMING FRICTION AND RESISTANCE NEGLIGIBLE ,THE TIME TAKEN IN REACHING EDGE OF DISC WILL BE 1.MAXIMUM IN GROOVE AB 2.MAXIMUM IN GROOVE AD 3.SAME IN ALL GROOVES 4.ACCORDING TO HEIGHT OF B, C, D, E, F
Answer» 11.A DISC IN WHICH SEVERAL GROOVES ARE CUT ALONG THE CHORD DRAWN FROM A POINT A, IS ARRANGED IN A VERTICLE PLANE , SEVERAL PARTICLES START SLIPPING FROM A ALONG GROOVES SIMULTANEOUSLY . ASSUMING FRICTION AND RESISTANCE NEGLIGIBLE ,THE TIME TAKEN IN REACHING EDGE OF DISC WILL BE 1.MAXIMUM IN GROOVE AB 2.MAXIMUM IN GROOVE AD 3.SAME IN ALL GROOVES 4.ACCORDING TO HEIGHT OF B, C, D, E, F

Discussion

33.	a particle is moving along a straight line and its position is given by the relation x=(t^3-6t^2-15t+40)mfind the time at which velocity is zero also position and displacementof the particle at that poi
Answer» a particle is moving along a straight line and its position is given by the relation x=(t^3-6t^2-15t+40)mfind the time at which velocity is zero also position and displacementof the particle at that poi

Discussion

34.	A p-n photodiode is fabricated from a semiconductor with band gapof 2.8 eV. Can it detect a wavelength of 6000 nm?
Answer» A p-n photodiode is fabricated from a semiconductor with band gapof 2.8 eV. Can it detect a wavelength of 6000 nm?

Discussion

35.	The incident intensity of light from the sun on a horizontal surface at sea level is about 1 kW/m2. Assuming that 50% of this light is reflected and 50% is absorbed, the radiation pressure on this horizontal surface will be -
Answer» The incident intensity of light from the sun on a horizontal surface at sea level is about $1 {kW/m}^{2}$ . Assuming that $50 %$ of this light is reflected and $50 %$ is absorbed, the radiation pressure on this horizontal surface will be -

Discussion

36.	What will be the geometry and shape of NH2-
Answer» What will be the geometry and shape of NH2-

Discussion

37.	A capacitor C=2 μF and an inductor with L=10 H and coil resistance 5 Ω are in series in a circuit. When an alternating current of rms value 2 A flows in the circuit, the average power (in W) in the circuit is
Answer» A capacitor $C = 2 μ F$ and an inductor with $L = 10 H$ and coil resistance $5 Ω$ are in series in a circuit. When an alternating current of $r m s$ value $2 A$ flows in the circuit, the average power $(in W)$ in the circuit is

Discussion

38.	if momentum is increased by 200% then kinetic energy increases by
Answer» if momentum is increased by 200% then kinetic energy increases by

Discussion

39.	The ratio of the acceleration for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is
Answer» The ratio of the acceleration for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is

Discussion

40.	Two concentric circular coils having 10 turns each are situated in the same plane. Their radii are 20 cm and 40 cm and they carry 0.2 A and 0.3 A current in opposite direction respectively. The magnetic field (in Wb m−2) at the centre is
Answer» Two concentric circular coils having $10$ turns each are situated in the same plane. Their radii are $20 cm$ and $40 cm$ and they carry $0.2 A$ and $0.3 A$ current in opposite direction respectively. The magnetic field $(in {Wb m}^{- 2})$ at the centre is

Discussion

41.	27 similar drops of mercury are maintained at 10 V each. All these spherical drops combine into a single big drop. The potential energy of the bigger drop is _______ times that of a smaller drop.
Answer» $27$ similar drops of mercury are maintained at $10 V$ each. All these spherical drops combine into a single big drop. The potential energy of the bigger drop is _______ times that of a smaller drop.

Discussion

42.	what is x ray diffraction?
Answer» what is x ray diffraction?

Discussion

43.	A spaceship of mass m0=500 kg moves in the absence of an external force with a constant velocity v0=50 m/s. To change the direction of motion, a jet engine is switched on. It starts ejecting a gas jet with velocity u=10 m/s which is constant relative to the spaceship and directed at right angles to the spaceship motion. The engine is shut down when the mass of the spaceship decreases to 400 kg. Through what angle α does the direction of motion of the spaceship deviate due to the jet engine operation? (Take ln(1.25)=0.223)
Answer» A spaceship of mass $m_{0} = 500 kg$ moves in the absence of an external force with a constant velocity $v_{0} = 50 m/s$ . To change the direction of motion, a jet engine is switched on. It starts ejecting a gas jet with velocity $u = 10 m/s$ which is constant relative to the spaceship and directed at right angles to the spaceship motion. The engine is shut down when the mass of the spaceship decreases to $400 kg$ . Through what angle $α$ does the direction of motion of the spaceship deviate due to the jet engine operation? (Take $ln (1.25) = 0.223$ )

Discussion

44.	In a vernier calipers , one main scale division is x cm and n divisions of the vernier scale coincide with (n−1) divisions of main scale. The least count (in cm) of the caliper is:
Answer» In a vernier calipers , one main scale division is $x cm$ and $n$ divisions of the vernier scale coincide with $(n - 1)$ divisions of main scale. The least count (in $cm$ ) of the caliper is:

Discussion

45.	2. During the first 18 min of a 60 min trip, a car has an averagespeed of 11 ms-1. What should be the average speed forremaining 42 min so that car is having an average speed of21ms for the entire trip?(a) 25.3 ms-1(c) 31 ms-1(b) 29.2 ms(d) 35.6 ms
Answer» 2. During the first 18 min of a 60 min trip, a car has an averagespeed of 11 ms-1. What should be the average speed forremaining 42 min so that car is having an average speed of21ms for the entire trip?(a) 25.3 ms-1(c) 31 ms-1(b) 29.2 ms(d) 35.6 ms

Discussion

46.	When equal charges are placed at the 5corners of the Pentagon. Why the electric field is zero at the middle point
Answer» When equal charges are placed at the 5corners of the Pentagon. Why the electric field is zero at the middle point

Discussion

47.	A bead B of mass ‘m’ can travel without friction on a smooth horizontal wire xx’. The bead is connected to a block of identical mass by an ideal string passing over an ideal pulley. The system, as shown, is in vertical plane. System is initially released from rest in the position shown. Initial acceleration of block A is:
Answer» A bead B of mass ‘m’ can travel without friction on a smooth horizontal wire xx’. The bead is connected to a block of identical mass by an ideal string passing over an ideal pulley. The system, as shown, is in vertical plane. System is initially released from rest in the position shown. Initial acceleration of block A is:

47.

A bead B of mass ‘m’ can travel without friction on a smooth horizontal wire xx’. The bead is connected to a block of identical mass by an ideal string passing over an ideal pulley. The system, as shown, is in vertical plane. System is initially released from rest in the position shown. Initial acceleration of block A is:

Answer»

A bead B of mass ‘m’ can travel without friction on a smooth horizontal wire xx’. The bead is connected to a block of identical mass by an ideal string passing over an ideal pulley. The system, as shown, is in vertical plane.

System is initially released from rest in the position shown. Initial acceleration of block A is:

Discussion

48.	If →A=2^i+3^j−^k and →B=−^i+3^j+4^k, then projection of →A on →B will be
Answer» If $\to A = 2^i + 3^j -^k$ and $\to B = -^i + 3^j + 4^k$ , then projection of $\to A$ on $\to B$ will be

Discussion

49.	Molecules of a gas behave like
Answer» Molecules of a gas behave like

Discussion

50.	If a disc of radius r is free to rotate about coplanar tangential axis is released from rest. When it takes to lower vertical position find the angular velocity.
Answer» If a disc of radius r is free to rotate about coplanar tangential axis is released from rest. When it takes to lower vertical position find the angular velocity.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The ration of rotational to kinetic energy for a hollow sphere in pure rolling motio

The rate of change of position with respect to time is called ___

The surface tension of water is 72 dyne/cm. Convert it in SI unit.

At time t = 0 sec a particle starts moving along the x-axis. If its kinetic energy increases uniformly with time ‘t’, the net force acting on it must be proportional to

At 298 K, the enthalpy of fusion of a solid (X) is 2.8 KJ mol−1 and the enthalpy of vaporisation of the liquid (X) is 98.2 KJ mol−1. The enthalpy of sublimation of the substance (X) in KJ mol−1 is . (in nearest integer)

Find avector in the direction of vector whichhas magnitude 8 units.

Two bodies of masses 3 kg and 6 kg possess kinetic energies of 6 J and 10 J respectively. What is the ratio of their linear momentum?

92. For a simple pendulum, graph between velocity (v) and displacement (x) is?

A deutron and an alpha particle are placed in an electric field. The force acting on them are F1 and F2 and their acceleration are a1 and a2 respectively then 1.F1=F2 2.F1>F2 3.a1=a2 4.a1 not equal to a2

Theacceleration due to gravity on the surface of moon is 1.7 ms–2.What is the time period of a simple pendulum on the surface of moonif its time period on the surface of earth is 3.5 s? (gon the surface of earth is 9.8 ms–2)

The area bounded by y=xe|x|, x− axis and |x|=1 is (in sq. units)

Given the speed-time graph of a golf ball shot from ground at t = 0. What will be the time of flight?

The potential difference between the surface of charged sphere (radius R) and at the distance 3R from the surface of sphere is V. The electric field at the distance which is equal to radius R from the surface will be:

Question 24 Suppose the distance between earth and sun becomes half of its present distance. What is likely to happen to life?

3218. In an inductor, the current I varies with time t as5A16 (A/s) t. If induced emf in the inductoris 5 mV, the self inductance of the inductor is(1) 3.75% 10-3H(2) 3.75% 10-4H(3) 3.125% 10-3H(4) 3.125% 10-4HSX

An enclosure of volume V contains a mixture of 8 g of oxygen, 14 g of nitrogen and 22 g of carbon- dioxide at absolute temperature T. The pressure of the mixture of gases is (R is universal gas constant)

why if the kinetic engy of a sytem is zero impkies(implies) its line momentum is also zsero(zero)?

The velocity-time graph of a particle in straight line motion is shown in figure. The particle starts its motion from origin. Find the average acceleration from 2 s to 6 s.

A certain region of a soap bubble reflects red light of wavelength λ=650 nm. What is the minimum thickness that this region of the soap bubble could have? Take the index of the refraction of the soap film to be 1.41.

The near-point of a person suffering from hypermetropia is at 50 cm from his eye. What is the nature and power of the lens needed to correct this defect? (Assume that the near-point of the normal eye is 25 cm).

The decrease in the value of g (wrt earth's surface) on going to a height R2 above the earth’s surface will be?

A sphere of radius R and charge Q is plaan imaginary sphere of radius 2R whose centrecoincides with the given sphere. The flux related toimaginary sphere isplaced inside(22Q4Q(3) E(4) E,

Magnetic moment due to the motion of the electron in nth energy state of hydrogen atom is proportional to

a particle is moving along a straight line and its position is given by the relation x=(t^3-6t^2-15t+40)mfind the time at which velocity is zero also position and displacementof the particle at that poi

A p-n photodiode is fabricated from a semiconductor with band gapof 2.8 eV. Can it detect a wavelength of 6000 nm?

The incident intensity of light from the sun on a horizontal surface at sea level is about 1 kW/m2. Assuming that 50% of this light is reflected and 50% is absorbed, the radiation pressure on this horizontal surface will be -

What will be the geometry and shape of NH2-

A capacitor C=2 μF and an inductor with L=10 H and coil resistance 5 Ω are in series in a circuit. When an alternating current of rms value 2 A flows in the circuit, the average power (in W) in the circuit is

if momentum is increased by 200% then kinetic energy increases by

The ratio of the acceleration for a solid sphere (mass m and radius R) rolling down an incline of angle θ without slipping and slipping down the incline without rolling is

Two concentric circular coils having 10 turns each are situated in the same plane. Their radii are 20 cm and 40 cm and they carry 0.2 A and 0.3 A current in opposite direction respectively. The magnetic field (in Wb m−2) at the centre is

27 similar drops of mercury are maintained at 10 V each. All these spherical drops combine into a single big drop. The potential energy of the bigger drop is _______ times that of a smaller drop.

what is x ray diffraction?

In a vernier calipers , one main scale division is x cm and n divisions of the vernier scale coincide with (n−1) divisions of main scale. The least count (in cm) of the caliper is:

2. During the first 18 min of a 60 min trip, a car has an averagespeed of 11 ms-1. What should be the average speed forremaining 42 min so that car is having an average speed of21ms for the entire trip?(a) 25.3 ms-1(c) 31 ms-1(b) 29.2 ms(d) 35.6 ms

When equal charges are placed at the 5corners of the Pentagon. Why the electric field is zero at the middle point

If →A=2^i+3^j−^k and →B=−^i+3^j+4^k, then projection of →A on →B will be

Molecules of a gas behave like

If a disc of radius r is free to rotate about coplanar tangential axis is released from rest. When it takes to lower vertical position find the angular velocity.