Electromagnetic Waves

If 0 denotes the permittivity of free space and E is the flux of the electric field through the area bounded by the closed surface, then dimensions of ( 0 d Edt ) are that of :

1. electric charge
2. electric field
3. electric current
4. electric potential

The unit of 2I 0 c is : (I = intensity of an electromagnetic wave, c = speed of light)

1. Vm
2. NC-1
3. NC
4. Nm

If an optical medium possesses a relative permeability of 10 and relative permittivity of 10.0885, then the velocity of light is greater in vacuum than that in this medium by times. ( 0 = 4 10-7 H/m, 0 = 8.85 10-12 F/m, c = 3 108 m/s)

The radiation pressure exerted by a 450 W light source on a perfectly reflecting surface placed 2 m away from it, is

1. 3 10-8 Pascals
2. 0
3. 1.5 10-8 Pascals
4. 6 10-8 Pascals

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the most appropriate answer from the options given below :

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
2. Both (A) and (R) are true but (R) is not the correct explanation of (A)
3. (A) is false but (R) is true
4. (A) is true but (R) is false

A plane electromagnetic wave propagates along the + x direction in free space. The components of the electric field, E and magnetic field, B vectors associated with the wave in Cartesian frame are

1. Ex, By
2. Ey, Bx
3. Ey, Bz
4. Ez, By

A parallel plate capacitor consisting of two circular plates of radius 10 cm is being charged by a constant current of 0.15 A. If the rate of change of potential difference between the plates is 7 108 V/s then the integer value of the distance between the parallel plates is (Take, 0=9 10-12 Fm, = 227) .

Due to presence of an em-wave whose electric component is given by E = 100 ( t - kx) NC-1 a cylinder of length 200 cm holds certain amount of em-energy inside it. If another cylinder of same length but half diameter than previous one holds same amount of em-energy, the magnitude of the electric field of the corresponding em-wave should be modified as

1. 50 ( t - kx) NC-1
2. 400 ( t - kx) NC-1
3. 200 ( t - kx) NC-1
4. 25 ( t - kx) NC-1

The magnetic field of an E.M. wave is given by B = ( 32 i + 12 j )30 [ (t - zc ) ] (S.I. Units). The corresponding electric field in S.I. units is:

1. E = ( 12 i + 32 j )30c [ (t + zc ) ]
2. E = ( 12 i - 32 j )30c [ (t - zc ) ]
3. E = ( 32 i - 12 j )30c [ (t + zc ) ]
4. E = ( 34 i + 14 j )30c [ (t - zc ) ]

Arrange the following in the ascending order of wavelength ( ) : Choose the most appropriate answer from the options given below :

1. 4 < 3 < 2 < 1
2. 4 < 2 < 3 < 1
3. 3 < 4 < 2 < 1
4. 4 < 3 < 1 < 2