Explanation:
Electromagnetic induction is the production of current by relative motion between a magnet and a coil.The phenomenon of producing electric current in a conductor by moving it perpendicular to a magnetic field or vice -versa, is called electro magnetic induction.
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The internal resistance of a cell of e.m.f. 12V is 5 
. It is connected across an unknown resistance. Voltage across the cell, when a current of 60 A is drawn from it, is
|
(a) 15 V |
(b) 12 V |
(c) 9 V |
(d) 6 V |
The output of OR gate is 1
|
(a) If both inputs are zero |
(b) If either or both inputs are 1 |
|
(c) Only if both input are 1 |
(d) If either input is zero |
Assertion : In everyday life the Doppler’s effect is observed readily for sound waves than light waves.
Reason : Velocity of light is greater than that of sound.
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
If half life of radium is 77 days. Its decay constant in day will be
|
(a) 3 |
(b) |
(c) 1 |
(d) 6 |
Two electric charges 12μC and -6 μC are placed 20 cm apart in air. There will be a point P on the line joining these charges and outside the region between them, at which the electric potential is zero. The distance of P from -6 μC charge is
|
(a) 0.10 m |
(b) 0.15 m |
(c) 0.20 m |
(d) 0.25 m |
We have two wires A and B of same mass and same material. The diameter of the wire A is half of that B. If the resistance of wire A is 24 ohm then the resistance of wire B will be
|
(a) 12 Ohm |
(b) 3.0 Ohm |
(c) 1.5 Ohm |
(d) None of the above |
