Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Four identical capacitors are connected as shown in diagram. When a battery of 6 V is connected between A and B, the charge stored is found to be 1.5. The value of  is

(a) 2.5

(b) 15

(c) 1.5

(d)  0.1

What is the equivalent resistance between A and B in the figure below if R = 3Ω

(a) 9 Ω

(b) 12 Ω

(c) 15 Ω

(d) None of these

The resistance of a galvanometer is 50 ohms and the current required to give full scale deflection is 100μA. In order to convert it into an ammeter, reading upto 10A, it is necessary to put a resistance of

(a) 5  in parallel	(b) 5  in parallel
(c)  in series	(d) 99,950  in series

The drift velocity of free electrons in a conductor is ‘v’ when a current ‘i’ is flowing in it.  If both the radius and current are doubled, then drift velocity will be

(a) v

(b)

(c)

(d)

Assertion :   At 0 K Germanium is a superconductor. 

Reason    :    At 0 K Germanium offers zero resistance.

(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.

The electric potential decreases uniformly from 120V to 80V as one moves on the x-axis from x = -1cm to x = + 1cm. The electric field at the origin.

1. Must be equal to 20Vcm^-1
2. May be equal to 20Vcm^-1
3. May be greater than 20Vcm^-1
4. May be lees than 20Vcm^-1

In a cyclotron, a charged particle.

The equivalent resistance between the points P and Q in the network given here is equal to (given r = )

(a)

(b) 1 W

(c)

(d) 2 W

The resolving power of a telescope depends on:

The particle that possesses half integral spin is: