When a plane polarised light is passed through an analyser and analyser is rotated through 90°, the intensity of the emerging light
|
(a) Varies between a maximum and minimum |
|
(b) Becomes zero |
|
(c) Does not vary |
|
(d) Varies between a maximum and zero |
(d) Varies between a maximum and zero
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The primary winding of transformer has 500 turns whereas its secondary has 5000 turns. The primary is connected to an ac supply of 20 V, 50 Hz. The secondary will have an output of
|
(a) 200 V, 50 Hz |
(b) 2 V, 50 Hz |
(c) 200 V, 500 Hz |
(d) 2 V, 5 Hz |
The bending of light as it passes from one medium into another is commonly known as:
$2\text{u}\cos\theta$
$\frac{\text{u}}{\cos\theta}$
$\frac{\text{2u}}{\cos\theta}$
$\text{u}\cos\theta$
In the circuit of a triode valve, there is no change in the plate current, when the plate potential is increased from 200 volt to 220 volt and the grid potential is decreased from – 0.5 volt to –1.3 volt. The amplification factor of this valve is
|
(a) 15 |
(b) 20 |
(c) 25 |
(d) 35 |
Which of the following is not a correct statement
|
(a) Resistivity of electrolytes decreases on increasing temperature |
|
(b) Resistance of mercury falls on decreasing its temperature |
|
(c) When joined in series a 40 W bulb glows more than a 60 W bulb |
|
(d) Resistance of 40 W bulb is less than the resistance of 60 W bulb |
Two wires of the same material are given. The first wire is twice as long as the second and has twice the diameter of the second. The resistance of the first will be
|
(a) Twice of the second |
(b) Half of the second |
|
(c) Equal to the second |
(d) Four times of the second |
ABC is an equilateral triangle. Charges + q are placed at each corner. The electric intensity at O will be
|
(a) |
(b) |
(c) Zero |
(d) |
The equivalent resistance between the points P and Q of the circuit given is
|
(a) |
(b) |
(c) 4 R |
(d) 2 R |
