Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A sphere of radius R has a uniform distribution of electric charge in its volume. At a distance x from its centre, for x < R, the electric field is directly proportional to

(a)

(b)

(c) x

(d)

The resultant reactance in an L - C - R circuit is.

10 wires (same length, same area, same material) are connected in parallel and each has 1 Ω resistance, then the equivalent resistance will be

(a) 10 Ω

(b) 1 W

(c) 0.1 W

(d) 0.001 W

Assertion :   When two coils are wound on each other, the mutual induction between the coils is maximum.

Reason     : Mutual induction does not depend on the orientation of the coils.

(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.

An endoscope is employed by a physician to view the internal parts of a body organ. It is based on the principle of

(a) Refraction	(b) Reflection
(c) Total internal reflectionn	(d) Dispersion

The counting rate observed from a radioactive source at t = 0 second was 1600 counts per second and at t = 8 seconds it was 100 counts per second. The counting rate observed, as counts per second at t = 6 seconds, will be

(a) 400

(b) 300

(c) 200

(d) 150

What will be the nature of charge on the metal paper clip of electroscope when a negatively charged body is brought in contact with it?