An infinitely long cylinder is kept parallel to an uniform magnetic field B directed along positive z axis. The direction of induced current as seen from the z axis will be
|
(a) Clockwise of the +ve z axis |
(b) Anticlockwise of the +ve z axis |
|
(c) Zero |
(d) Along the magnetic field |
(c) Zero
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The focal length of a convex lens is 10 cm and its refractive index is 1.5. If the radius of curvature of one surface is 7.5 cm, the radius of curvature of the second surface will be
|
(a) 7.5 cm |
(b) 15.0 cm |
(c) 75 cm |
(d) 5.0 cm |
A rectangular coil of 20 turns and area of cross- section 25 sq cm has a resistance of 100 ohm. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of 1000 Tesla per second, the current in the coil is
|
(a) 1.0 ampere |
(b) 50 ampere |
(c) 0.5 ampere |
(d) 5.0 ampere |
The correct relation is (Where 
Horizontal component of earth's magnetic field; 
= Vertical component of earth's magnetic field and B = Total intensity of earth's magnetic field)
(a) B = 
|
(b) 
|
(c) |B| = 
|
(d) 
|
If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be
|
(a) 50 Hz |
(b) 70.7 Hz |
(c) 100 Hz |
(d) 25 Hz |
The half life of polonium is 140 days. After how many days, 16 gm polonium will be reduced to 1 gm (or 15g will decay)
|
(a) 700 days |
(b) 280 days |
(c) 560 days |
(d) 420 days |