50278 + Interview Questions in Physics Page 93 InterviewSolution

4601.	E (potential) of an electrode is extensive or intensiv properit
Answer» E (potential) of an electrode is extensive or intensiv properit

Discussion

4602.	63.when an ideal capacitor is charged by aDC battery, no current flows.However, when an AC source is used , the current flows continuously. How does one explain this , based on the concept of displacement current?
Answer» 63.when an ideal capacitor is charged by aDC battery, no current flows.However, when an AC source is used , the current flows continuously. How does one explain this , based on the concept of displacement current?

Discussion

4603.	A sphere of mass 1 kg rests at one corner of a box. The box is then moved with a velocity →v=8t ^i−2t2^j. Where t is time in second. The force by sphere on the box at t=1 s is (g=10 ms−2) [Figure shows vertical plane of the box]
Answer» A sphere of mass $1 kg$ rests at one corner of a box. The box is then moved with a velocity $\to v = 8 t^i - 2 t^{2}^j$ . Where $t$ is time in second. The force by sphere on the box at $t = 1 s$ is ( $g = 10 {ms}^{- 2}$ ) [Figure shows vertical plane of the box]

Discussion

4604.	A weight mg is suspended from a spring. If the energy stored in the spring is U. The elongation in the spring is
Answer» A weight mg is suspended from a spring. If the energy stored in the spring is U. The elongation in the spring is

Discussion

4605.	In column 1 different setup for Young’s double slit experiment is given. Distance between two slits S1 and S2 is ‘d’ and between slits and screen is ‘D’ in every setup. In column 2 location of central maxima is given. In column 3 path difference ΔP is given at point P which is θ angle above MO line (d << D) Which of the following is correct when light is incident at an angle θ0?
Answer» In column 1 different setup for Young’s double slit experiment is given. Distance between two slits S1 and S2 is ‘d’ and between slits and screen is ‘D’ in every setup. In column 2 location of central maxima is given. In column 3 path difference $Δ P$ is given at point P which is $θ$ angle above MO line (d << D) Which of the following is correct when light is incident at an angle $θ_{0}$ ?

Discussion

4606.	If →a=2^i+^j+2^k, then the value of ∣∣^i×(→a×^i)∣∣2+∣∣^j×(→a×^j)∣∣2+∣∣^k×(→a×^k)∣∣2 is equal to
Answer» If $\to a = 2^i +^j + 2^k,$ then the value of ${∣ ∣^i \times (\to a \times^i) ∣ ∣}^{2} + {∣ ∣^j \times (\to a \times^j) ∣ ∣}^{2} + {∣ ∣^k \times (\to a \times^k) ∣ ∣}^{2}$ is equal to

Discussion

4607.	A particle travelling in a straight path in the same direction covers the first half of the distance with a velocity v1 and the second half of the distance with two different velocities v2 and v3 in equal intervals of time. The average velocity of the particle for the entire journey is
Answer» A particle travelling in a straight path in the same direction covers the first half of the distance with a velocity $v_{1}$ and the second half of the distance with two different velocities $v_{2}$ and $v_{3}$ in equal intervals of time. The average velocity of the particle for the entire journey is

Discussion

4608.	In scattering experiment find the distance of closest approach if a 6MeV alpha -particle is used (1) 3.2times10^(-16)m (2) 3.79times10^(-14)m (3) 4.6times10^(-15)m (4) 3.2times10^(-15)m
Answer» In scattering experiment find the distance of closest approach if a 6MeV alpha -particle is used (1) 3.2times10^(-16)m (2) 3.79times10^(-14)m (3) 4.6times10^(-15)m (4) 3.2times10^(-15)m

Discussion

4609.	A car travelling at a speed of 80 kmph is brought to a speed of 60 kmph within a distance of 30 m by applying brakes. On travelling further at a speed of 60 kmph, the driver of the car saw an overturned truck across and he applied the brakes again. The car stopped just close to the overturned vehicle. What was the distance (in kmph) between the overturned truck and the car when the driver first saw the overturned truck? The reaction time of the driver may be taken as 2 seconds.71.86
Answer» A car travelling at a speed of 80 kmph is brought to a speed of 60 kmph within a distance of 30 m by applying brakes. On travelling further at a speed of 60 kmph, the driver of the car saw an overturned truck across and he applied the brakes again. The car stopped just close to the overturned vehicle. What was the distance (in kmph) between the overturned truck and the car when the driver first saw the overturned truck? The reaction time of the driver may be taken as 2 seconds. 71.86

4609.

A car travelling at a speed of 80 kmph is brought to a speed of 60 kmph within a distance of 30 m by applying brakes. On travelling further at a speed of 60 kmph, the driver of the car saw an overturned truck across and he applied the brakes again. The car stopped just close to the overturned vehicle. What was the distance (in kmph) between the overturned truck and the car when the driver first saw the overturned truck? The reaction time of the driver may be taken as 2 seconds.71.86

Answer»

A car travelling at a speed of 80 kmph is brought to a speed of 60 kmph within a distance of 30 m by applying brakes. On travelling further at a speed of 60 kmph, the driver of the car saw an overturned truck across and he applied the brakes again. The car stopped just close to the overturned vehicle. What was the distance (in kmph) between the overturned truck and the car when the driver first saw the overturned truck? The reaction time of the driver may be taken as 2 seconds.

71.86

Discussion

4610.	If an object is vibrating at 10 hertz, what is its time period?
Answer» If an object is vibrating at 10 hertz, what is its time period?

Discussion

4611.	The Bob of a simple pendulum is replaced by a magnet. The oscillation are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is shortcircuted. Then which of the following happens? 1) period does not change 2) Oscillations are damped 3) amplitude increases 4) period decreases
Answer» The Bob of a simple pendulum is replaced by a magnet. The oscillation are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is shortcircuted. Then which of the following happens? 1) period does not change 2) Oscillations are damped 3) amplitude increases 4) period decreases

Discussion

4612.	If a black body is heated at a high temperature, it seems to be
Answer» If a black body is heated at a high temperature, it seems to be

Discussion

4613.	51.The following arrangement consists of five identical metal plates parallel to each other.Area of each plate is A and separation between the succesive plate is d.The capacitence between P and Q is
Answer» 51.The following arrangement consists of five identical metal plates parallel to each other.Area of each plate is A and separation between the succesive plate is d.The capacitence between P and Q is

Discussion

4614.	The current in a disharging LR circuit without the battery drops from 2.0 A to 1.0 A in 0.10 s. (a) Find the time constant of the circuit (b) If the inducatance of the circuit is 4.0 H, what is its resistance?
Answer» The current in a disharging LR circuit without the battery drops from 2.0 A to 1.0 A in 0.10 s. (a) Find the time constant of the circuit (b) If the inducatance of the circuit is 4.0 H, what is its resistance?

Discussion

4615.	What is a domain?
Answer» What is a domain?

Discussion

4616.	A man is standing on a cart which has a mass double that of the man as shown in the figure. Initially, the cart is at rest. Now, the man jumps horizontally with velocity 2 m/s relative to the cart. Then work done by the man during the process of jumping will be
Answer» A man is standing on a cart which has a mass double that of the man as shown in the figure. Initially, the cart is at rest. Now, the man jumps horizontally with velocity $2 m/s$ relative to the cart. Then work done by the man during the process of jumping will be

Discussion

4617.	A particle of mass 40 g executes a simple harmonic motion of amplitude 2.0 cm. If the time period is 0.20 s, find the total mechanical energy of the system.
Answer» A particle of mass 40 g executes a simple harmonic motion of amplitude 2.0 cm. If the time period is 0.20 s, find the total mechanical energy of the system.

Discussion

4618.	The Bohr radius is given by a0=ϵ0h2πme2. Verify that the RHS has dimensions of length.
Answer» The Bohr radius is given by $a^{0} = \frac{ϵ_{0} h^{2}}{π m e^{2}}$ . Verify that the RHS has dimensions of length.

Discussion

4619.	A parallel plate capacitor with plate area 100 cm2 and seperation between the plates 1.0 cm is connected across a battery of emf 24 V. The force of attraction between the plates is
Answer» A parallel plate capacitor with plate area $100 {cm}^{2}$ and seperation between the plates $1.0 cm$ is connected across a battery of emf $24 V$ . The force of attraction between the plates is

Discussion

4620.	A point mass m moving with velocity v0 hits a ball of same mass m at rest elastically. After the collision, point mass moves with velocity v0/2 at an angle θ from initial direction of motion. Then value of θ is
Answer» A point mass $m$ moving with velocity $v_{0}$ hits a ball of same mass $m$ at rest elastically. After the collision, point mass moves with velocity $v_{0} / 2$ at an angle $θ$ from initial direction of motion. Then value of $θ$ is

Discussion

4621.	Find the current between point A and B from given figure.
Answer» Find the current between point $A$ and $B$ from given figure.

Discussion

4622.	The specific conductance of a 0.1 N KCl solution at 23° C is 0.012 ohm-1 cm-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be [CBSE PMT 1999, 2000; KCET 2001]
Answer» The specific conductance of a 0.1 N KCl solution at 23° C is 0.012 ohm^-1cm^-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be [CBSE PMT 1999, 2000; KCET 2001]

Discussion

4623.	78.What are the 3 messures of biocontrol of pests
Answer» 78.What are the 3 messures of biocontrol of pests

Discussion

4624.	An object accelerates from rest to a velocity 27.5 ms−1 in 10 sec. Find the distance covered by the object (in meter)during next 10 sec.
Answer» An object accelerates from rest to a velocity $27.5 {ms}^{- 1}$ in $10$ sec. Find the distance covered by the object (in meter)during next $10$ sec.

Discussion

4625.	63. A disc of mass m and radius r is free to rotate about it's centre as shown in the figure. A string is wrapped over it's rim and a block of mass m is attached to the end of the string. The system is released from rest. The speed of the block as it descends through a height h, is
Answer» 63. A disc of mass m and radius r is free to rotate about it's centre as shown in the figure. A string is wrapped over it's rim and a block of mass m is attached to the end of the string. The system is released from rest. The speed of the block as it descends through a height h, is

Discussion

4626.	A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windingsof 300 turns each. A 2.0 cm long wire of mass 2.5 g lies inside thesolenoid (near its centre) normal to its axis; both the wire and theaxis of the solenoid are in the horizontal plane. The wire is connectedthrough two leads parallel to the axis of the solenoid to an externalbattery which supplies a current of 6.0 A in the wire. What value ofcurrent (with appropriate sense of circulation) in the windings ofthe solenoid can support the weight of the wire? g = 9.8 m s–2.
Answer» A solenoid 60 cm long and of radius 4.0 cm has 3 layers of windingsof 300 turns each. A 2.0 cm long wire of mass 2.5 g lies inside thesolenoid (near its centre) normal to its axis; both the wire and theaxis of the solenoid are in the horizontal plane. The wire is connectedthrough two leads parallel to the axis of the solenoid to an externalbattery which supplies a current of 6.0 A in the wire. What value ofcurrent (with appropriate sense of circulation) in the windings ofthe solenoid can support the weight of the wire? g = 9.8 m s–2.

Discussion

4627.	In the circuit shown in the figure, the reading of the voltmeter V will be
Answer» In the circuit shown in the figure, the reading of the voltmeter $V$ will be

Discussion

4628.	A 10 gram bullet having a charge of 4 micro coulomb is fired at a speed of 270 m/s in a horizontal direction. A vertical magnetic field of 500 micro Tesla exists in the space. Find the deflection of the bullet due to the magnetic field as it travels through 100 metres.
Answer» A 10 gram bullet having a charge of 4 micro coulomb is fired at a speed of 270 m/s in a horizontal direction. A vertical magnetic field of 500 micro Tesla exists in the space. Find the deflection of the bullet due to the magnetic field as it travels through 100 metres.

Discussion

4629.	Let [ε0] denote the dimensional formula of the permittivity of the vaccum and [μ0] denote the permeability of the vacuum. If M= mass, L= length, T= time and I= electric current, then
Answer» Let $[ε_{0}]$ denote the dimensional formula of the permittivity of the vaccum and $[μ_{0}]$ denote the permeability of the vacuum. If $M$ = mass, $L =$ length, $T =$ time and $I =$ electric current, then

Discussion

4630.	Two waves of the same frequency and same amplitude are superimposed to produce a resultant disturbance wave of the same amplitude. What is the phase difference between the two original waves?
Answer» Two waves of the same frequency and same amplitude are superimposed to produce a resultant disturbance wave of the same amplitude. What is the phase difference between the two original waves?

Discussion

4631.	a flexible spherical shell.of radius r with uniformly distributed charge q is expanded to radius 2r. the work.done by the electric force in this process
Answer» a flexible spherical shell.of radius r with uniformly distributed charge q is expanded to radius 2r. the work.done by the electric force in this process

Discussion

4632.	in an apparatus , the elecric field was found to oscillate with an amplitude of 18 Vm^{-1}. the magnitude of the oscillating magnetic field will be
Answer» in an apparatus , the elecric field was found to oscillate with an amplitude of 18 Vm^{-1}. the magnitude of the oscillating magnetic field will be

Discussion

4633.	if a star is moving towards the earth with a relative velocity of 0.8c.Then what is the frequency of the light observedby the observer on the earth if it emits light of 6000 hz. and what will be the frequency observed if the star moves away from eart
Answer» if a star is moving towards the earth with a relative velocity of 0.8c.Then what is the frequency of the light observedby the observer on the earth if it emits light of 6000 hz. and what will be the frequency observed if the star moves away from eart

Discussion

4634.	An alpha particle, a proton, a deutron and a neutron are projected towards the same nucleus with the same kinetic energy in different experiments. The distance of closet approach is minimum for
Answer» An alpha particle, a proton, a deutron and a neutron are projected towards the same nucleus with the same kinetic energy in different experiments. The distance of closet approach is minimum for

Discussion

4635.	A plane EM wave of frequency 25 MHz travels in free space in x-direction. At a particular point in space and time →E=6.3 Vm−1^j then B at that point is-
Answer» A plane $EM$ wave of frequency $25 MHz$ travels in free space in $x$ -direction. At a particular point in space and time $\to E = 6.3 {Vm}^{- 1}^j$ then $B$ at that point is-

Discussion

4636.	A charge q is placed at the centre O of cube of length L. Another same charge q is placed at a dis†an ce L from O. Then electric flux through face ABCD i
Answer» A charge q is placed at the centre O of cube of length L. Another same charge q is placed at a dis†an ce L from O. Then electric flux through face ABCD i

Discussion

4637.	case 1) 1 resistor(50 ohm) and inductor( 50 ohm) are joined in series to ac source 220volt, what is voltage on each of them? case 2) 1 resistor 50 ohm and inductor also 50 ohm are connected to dc source 220 volt , what is voltage on them? what is power in each case
Answer» case 1) 1 resistor(50 ohm) and inductor( 50 ohm) are joined in series to ac source 220volt, what is voltage on each of them? case 2) 1 resistor 50 ohm and inductor also 50 ohm are connected to dc source 220 volt , what is voltage on them? what is power in each case

Discussion

4638.	How light goes through transparent medium but not in opaque
Answer» How light goes through transparent medium but not in opaque

Discussion

4639.	In each of the three arrangements, the block of mass m1 is being pulled left with constant velocity. All surfaces are smooth. The strings are light and inextensible and pulleys are massless. The ratio of the speed of the block of mass m2 in the three cases respectively is:
Answer» In each of the three arrangements, the block of mass m₁ is being pulled left with constant velocity. All surfaces are smooth. The strings are light and inextensible and pulleys are massless. The ratio of the speed of the block of mass $m_{2}$ in the three cases respectively is:

4639.

In each of the three arrangements, the block of mass m1 is being pulled left with constant velocity. All surfaces are smooth. The strings are light and inextensible and pulleys are massless. The ratio of the speed of the block of mass m2 in the three cases respectively is:

Answer»

In each of the three arrangements, the block of mass m₁ is being pulled left with constant velocity. All surfaces are smooth. The strings are light and inextensible and pulleys are massless. The ratio of the speed of the block of mass $m_{2}$ in the three cases respectively is:

Discussion

4640.	A body is moving on a circle of radius 80 metre with speed 20 metre per second which is decreasing at the rate of 5 metre per second square at an instant the angle made by its acceleration with its velocity is
Answer» A body is moving on a circle of radius 80 metre with speed 20 metre per second which is decreasing at the rate of 5 metre per second square at an instant the angle made by its acceleration with its velocity is

Discussion

4641.	A ball is thrown at a triangular wedge with an angle of inclination 60o parallel to the ground as shown in the figure. After bouncing against the wedge, the velocity of the ball is perpendicular to the ground. What is the coefficient of restitution?
Answer» A ball is thrown at a triangular wedge with an angle of inclination $60^{o}$ parallel to the ground as shown in the figure. After bouncing against the wedge, the velocity of the ball is perpendicular to the ground. What is the coefficient of restitution?

Discussion

4642.	26. Calculate emf of the cell Fe +H+(1M)---->Fe(0.001M)+H2(1atm)
Answer» 26. Calculate emf of the cell Fe +H+(1M)---->Fe(0.001M)+H2(1atm)

Discussion

4643.	a particle moving along x-axis has acceleration f,at time t, given by f=f'(1-t/T), where f' and T are cons†an ts.The particle at t=0 has zero velocity.At the ins†an t when f=0,the particle,s velocity is
Answer» a particle moving along x-axis has acceleration f,at time t, given by f=f'(1-t/T), where f' and T are cons†an ts.The particle at t=0 has zero velocity.At the ins†an t when f=0,the particle,s velocity is

Discussion

4644.	If α kilogram, β meter, and γ second are the fundamental units, 1 cal can be expressed in new units as [1 cal=4.2 J]
Answer» If $α kilogram$ , $β meter$ , and $γ second$ are the fundamental units, $1 cal$ can be expressed in new units as $[1 cal = 4.2 J]$

Discussion

4645.	Two pendulums of same amplitude but time period 3s and 7s start oscillating simultaneously from two opposite extreme positions. After how much time they will be in phase.
Answer» Two pendulums of same amplitude but time period 3s and 7s start oscillating simultaneously from two opposite extreme positions. After how much time they will be in phase.

Discussion

4646.	The angular velocity of a particle moving in a circle of radius 50 cm is increased in 5 min from 100 revolutions per minute to 400 revolutions per minute. Find the tangential acceleration of the particle.
Answer» The angular velocity of a particle moving in a circle of radius $50 c m$ is increased in $5$ min from $100$ revolutions per minute to $400$ revolutions per minute. Find the tangential acceleration of the particle.

Discussion

4647.	The equation of tangent to the curve x2+y2=8 at (2,−2) is[1 mark]
Answer» The equation of tangent to the curve $x^{2} + y^{2} = 8$ at $(2, - 2)$ is [1 mark]

Discussion

4648.	A small circular loop of radius l=1 cm is kept inside a larger circular loop of radius r such that both are coplanar and concentric. If the current in larger loop is as shown in the graph, then current induced in the smaller loop any time is represented as In at any instant. Take anticlockwise current as positive. List -1 contains time instants, and List-2 contains the values for In. Match them. Take μ0π2Rr=1. List -1List -2(I)0 sec(p)25μA(II)13sec(Q)12.5μA(III)32sec(R)0μA(IV)53sec(S)−6.25μA(T)−12.5μA(U)−25μA
Answer» A small circular loop of radius $l = 1 c m$ is kept inside a larger circular loop of radius r such that both are coplanar and concentric. If the current in larger loop is as shown in the graph, then current induced in the smaller loop any time is represented as $I_{n}$ at any instant. Take anticlockwise current as positive. List -1 contains time instants, and List-2 contains the values for $I_{n}$ . Match them. Take $\frac{μ_{0} π}{2 R r} = 1$ . $\begin{matrix} List -1 & List -2 (I) & 0 s e c & (p) & 25 μ A (I I) & \frac{1}{3} s e c & (Q) & 12.5 μ A (I I I) & \frac{3}{2} s e c & (R) & 0 μ A (I V) & \frac{5}{3} s e c & (S) & - 6.25 μ A (T) & - 12.5 μ A (U) & - 25 μ A \end{matrix}$

Discussion

4649.	Two solid rubber balls A and B having masses 200 and 400 gm respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is
Answer» Two solid rubber balls A and B having masses 200 and 400 gm respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is

Discussion

4650.	How the vacancy holes help in conductivity in p-type of semiconductor .Describe it.
Answer» How the vacancy holes help in conductivity in p-type of semiconductor .Describe it.

Discussion

Explore topic-wise InterviewSolutions in .

E (potential) of an electrode is extensive or intensiv properit

63.when an ideal capacitor is charged by aDC battery, no current flows.However, when an AC source is used , the current flows continuously. How does one explain this , based on the concept of displacement current?

A sphere of mass 1 kg rests at one corner of a box. The box is then moved with a velocity →v=8t ^i−2t2^j. Where t is time in second. The force by sphere on the box at t=1 s is (g=10 ms−2) [Figure shows vertical plane of the box]

A weight mg is suspended from a spring. If the energy stored in the spring is U. The elongation in the spring is

If →a=2^i+^j+2^k, then the value of ∣∣^i×(→a×^i)∣∣2+∣∣^j×(→a×^j)∣∣2+∣∣^k×(→a×^k)∣∣2 is equal to

A particle travelling in a straight path in the same direction covers the first half of the distance with a velocity v1 and the second half of the distance with two different velocities v2 and v3 in equal intervals of time. The average velocity of the particle for the entire journey is

In scattering experiment find the distance of closest approach if a 6MeV alpha -particle is used (1) 3.2times10^(-16)m (2) 3.79times10^(-14)m (3) 4.6times10^(-15)m (4) 3.2times10^(-15)m

If an object is vibrating at 10 hertz, what is its time period?

If a black body is heated at a high temperature, it seems to be

51.The following arrangement consists of five identical metal plates parallel to each other.Area of each plate is A and separation between the succesive plate is d.The capacitence between P and Q is

The current in a disharging LR circuit without the battery drops from 2.0 A to 1.0 A in 0.10 s. (a) Find the time constant of the circuit (b) If the inducatance of the circuit is 4.0 H, what is its resistance?

What is a domain?

A man is standing on a cart which has a mass double that of the man as shown in the figure. Initially, the cart is at rest. Now, the man jumps horizontally with velocity 2 m/s relative to the cart. Then work done by the man during the process of jumping will be

A particle of mass 40 g executes a simple harmonic motion of amplitude 2.0 cm. If the time period is 0.20 s, find the total mechanical energy of the system.

The Bohr radius is given by a0=ϵ0h2πme2. Verify that the RHS has dimensions of length.

A parallel plate capacitor with plate area 100 cm2 and seperation between the plates 1.0 cm is connected across a battery of emf 24 V. The force of attraction between the plates is

A point mass m moving with velocity v0 hits a ball of same mass m at rest elastically. After the collision, point mass moves with velocity v0/2 at an angle θ from initial direction of motion. Then value of θ is

Find the current between point A and B from given figure.

The specific conductance of a 0.1 N KCl solution at 23° C is 0.012 ohm-1 cm-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be [CBSE PMT 1999, 2000; KCET 2001]

78.What are the 3 messures of biocontrol of pests

An object accelerates from rest to a velocity 27.5 ms−1 in 10 sec. Find the distance covered by the object (in meter)during next 10 sec.

63. A disc of mass m and radius r is free to rotate about it's centre as shown in the figure. A string is wrapped over it's rim and a block of mass m is attached to the end of the string. The system is released from rest. The speed of the block as it descends through a height h, is

In the circuit shown in the figure, the reading of the voltmeter V will be

A 10 gram bullet having a charge of 4 micro coulomb is fired at a speed of 270 m/s in a horizontal direction. A vertical magnetic field of 500 micro Tesla exists in the space. Find the deflection of the bullet due to the magnetic field as it travels through 100 metres.

Let [ε0] denote the dimensional formula of the permittivity of the vaccum and [μ0] denote the permeability of the vacuum. If M= mass, L= length, T= time and I= electric current, then

Two waves of the same frequency and same amplitude are superimposed to produce a resultant disturbance wave of the same amplitude. What is the phase difference between the two original waves?

a flexible spherical shell.of radius r with uniformly distributed charge q is expanded to radius 2r. the work.done by the electric force in this process

in an apparatus , the elecric field was found to oscillate with an amplitude of 18 Vm^{-1}. the magnitude of the oscillating magnetic field will be

if a star is moving towards the earth with a relative velocity of 0.8c.Then what is the frequency of the light observedby the observer on the earth if it emits light of 6000 hz. and what will be the frequency observed if the star moves away from eart

An alpha particle, a proton, a deutron and a neutron are projected towards the same nucleus with the same kinetic energy in different experiments. The distance of closet approach is minimum for

A plane EM wave of frequency 25 MHz travels in free space in x-direction. At a particular point in space and time →E=6.3 Vm−1^j then B at that point is-

A charge q is placed at the centre O of cube of length L. Another same charge q is placed at a dis†an ce L from O. Then electric flux through face ABCD i

case 1) 1 resistor(50 ohm) and inductor( 50 ohm) are joined in series to ac source 220volt, what is voltage on each of them? case 2) 1 resistor 50 ohm and inductor also 50 ohm are connected to dc source 220 volt , what is voltage on them? what is power in each case

How light goes through transparent medium but not in opaque

In each of the three arrangements, the block of mass m1 is being pulled left with constant velocity. All surfaces are smooth. The strings are light and inextensible and pulleys are massless. The ratio of the speed of the block of mass m2 in the three cases respectively is:

A body is moving on a circle of radius 80 metre with speed 20 metre per second which is decreasing at the rate of 5 metre per second square at an instant the angle made by its acceleration with its velocity is

A ball is thrown at a triangular wedge with an angle of inclination 60o parallel to the ground as shown in the figure. After bouncing against the wedge, the velocity of the ball is perpendicular to the ground. What is the coefficient of restitution?

26. Calculate emf of the cell Fe +H+(1M)---->Fe(0.001M)+H2(1atm)

a particle moving along x-axis has acceleration f,at time t, given by f=f'(1-t/T), where f' and T are cons†an ts.The particle at t=0 has zero velocity.At the ins†an t when f=0,the particle,s velocity is

If α kilogram, β meter, and γ second are the fundamental units, 1 cal can be expressed in new units as [1 cal=4.2 J]

Two pendulums of same amplitude but time period 3s and 7s start oscillating simultaneously from two opposite extreme positions. After how much time they will be in phase.

The angular velocity of a particle moving in a circle of radius 50 cm is increased in 5 min from 100 revolutions per minute to 400 revolutions per minute. Find the tangential acceleration of the particle.

The equation of tangent to the curve x2+y2=8 at (2,−2) is[1 mark]

Two solid rubber balls A and B having masses 200 and 400 gm respectively are moving in opposite directions with velocity of A equal to 0.3 m/s. After collision the two balls come to rest, then the velocity of B is

How the vacancy holes help in conductivity in p-type of semiconductor .Describe it.