Explanation:
For electromagnetic waves E and B are always perpendicular to each other and perpendicular to the direction of propagation. The direction of propagation is the direction of E × B.
The direction of propagation of the wave is the direction of propagation of its energy and power.
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The mutual inductance between two coils is 1.25 henry. If the current in the primary changes at the rate of 80 ampere/second, then the induced e.m.f. in the secondary is
|
(a) 12.5 V |
(b) 64.0 V |
(c) 0.016 V |
(d) 100.0 V |
For the transistor circuit shown below, if b = 100, voltage drop between emitter and base is 0.7 V then value of VCE will be
|
(a) 10 V |
(b) 5 V |
(c) 13 V |
(d) 0 V |
Force of attraction between two point charges Q and -Q separated by d metre is 
. When these charges are placed on two identical spheres of radius R = 0.3d whose centres are d metre apart, the force of attraction between them is
|
(a) Greater than
|
(b) Equal to
|
(c) Less than |
(d) Less than |
For production of characteristic 
X-rays, the electron transition is
|
(a) n = 2 to n = 1 |
(b) n = 3 to n = 2 |
(c) n = 3 to n = 1 |
(d) n = 4 to n = 2 |