Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

The magnetic flux linked with a coil is given by an equation ∅ (in webers) = . The induced e.m.f. in the coil at the fourth second will be

(a) 16 units

(b) 39 units

(c) 67 units

(d) 145 units

What is the driving force in a working Electrical Circuit?

An electron in the n = 1 orbit of hydrogen atom is bound by 13.6 eV energy is required to ionize it is

(a) 13.6 eV

(b) 6.53 eV

(c) 5.4 eV

(d) 1.51 eV

A 10   capacitor and a 20  capacitor are connected in series across a 200 V supply line. The charged capacitors are then disconnected from the line and reconnected with their positive plates together and negative plates together and no external voltage is applied. What is the potential difference across each capacitor

(a)

(b)

(c) 400 V

(d) 200 V

In an FM system a 7 kHz signal modulates 108 MHz carrier so that frequency deviation is 50 kHz. The carrier swing is

(a) 7.143

(b) 8

(c) 0.71

(d) 350

Approximate height of ozone layer above the ground is

(a) 60 to 70 km

(b) 59 km to 80 km

(c) 70 km to 100 km

(d) 100 km to 200 km

The most commonly used material for making transistor is

(a) Copper

(b) Silicon

(c) Ebonite

(d) Silver

The  emf of a battery  is 2 V  and  its  internal  resistance is 0.5 W. The maximum power which it can deliver to any external circuit will be

(a) 8 Watt

(b) 4 Watt

(c) 2 Watt

(d) None of the above

The half-life of a radioactive substance against a-decay is 1.2 . What is the decay rate for 4  atoms of the substance

(a) 4.6	(b) 2.3
(c) 4.6	(d) 2.3

______ of a two particle system depends only on the separation between the two particles. The most appropriate choice for the blank space in the above sentence is:

1. Kinetic energy.
2. Total mechanical energy.
3. Potential energy.
4. Total energy.