In an electromagnetic wave:
1. | power is transmitted along the magnetic field. |
2. | power is transmitted along the electric field. |
3. | power is equally transferred along with the electric and magnetic fields. |
4. | power is transmitted in a direction perpendicular to both the fields. |
For any E.M. wave if E = 100 V/m and B = 0.265 Then the rate of maximum energy flow per unit area is:
(1)
(2) 26.5 W/
(3)
(4) None of these
A variable frequency AC source is connected to a capacitor. Then on increasing the frequency
(1) Both conduction current and displacement current will increase
(2) Both conduction current and displacement current will decrease
(3) Conduction current will increase and displacement will decrease
(4) Conduction current will decrease and displacement current will increase
Instantaneous displacement current of 2.0 A is set up in the space between two parallel plates of 1 capacitor. The rate of change in potential difference across the capacitor is-
(1)
(2)
(3)
(4) none of these
Which of the following have zero average value in a plane electromagnetic wave?
(1) electric field
(2) magnetic field
(3) magnetic & electric field both
(4) none of these
In a plane electromagnetic wave propagating in space has an electric field of amplitude V/m, then the amplitude of the magnetic field is
(1)
(2)
(3)
(4)
A radiowave has a maximum magnetic field induction of T on arrival at a receiving antenna. The maximum electric field intensity of such a wave is
(1) zero
(2)
(3)
(4)
A capacitor is having a capacity of 2 pF. The electric potential across the capacitor is changing with a value of V/s. The displacement current is :
(1) 2 A
(2) 3 A
(3) 6 A
(4) 9 A
X-rays and -rays are both electromagnetic waves, which one of the following statements is true?
(1) in general, X-rays have a larger wavelength than that of -rays
(2) X-rays have a smaller wavelength than that of -rays
(3) -rays have smaller frequency than that of X-rays
(4) wavelength and frequency of X-rays are both larger than those of -rays.
The frequencies of X-rays, -rays and ultraviolet rays are respectively a, b and c. Then :
(1) a < b, b < c
(2) a > b, b > c
(3) a > b, b > a
(4) a < b, b > c