Moving Charges and Magnetism — Physics STD 12 Science — Question

Indirect method of charging is:

In order to forward bias a PN junction, the negative terminal of battery is connected to

(a) P–side	(b) Either P–side or N–side
(c) N–side	(d) None of these

A milliammeter of range 10 mA has a coil of resistance 1 W.  To use it as voltmeter of range 10 volt, the resistance that must be connected in series with it, will be

(a) 999 W

(b) 99 W

(c) 1000 W

(d) None of these

A capacitor of 4μ F is connected as shown in the circuit (Fig.). The internal resistance of the battery is 0.5Ω. The amount of charge on the capacitor plates will be:

Two parallel plates separated by a distance of 5mm are kept at a potential difference of 50 V. A particle  of mass   and charge   enters in it with a velocity .  The acceleration of the particle will be

(a)

(b)

(c)

(d) 2

A coil is wound as a transformer of rectangular cross-section. If all the linear dimensions of the transformer are increased by a factor 2 and the number of turns per unit length of the coil remain the same, the self  inductance increased by a factor of

(a)  16

(b) 12

(c)  8

(d) 4

Magnetic lines of force:

The total work done on a particle is equal to the change in its kinetic energy:

1. Always.
2. Only if the forces acting on it are conservative.
3. Only if gravitational force alone acts on it.
4. Only if elastic force alone acts on it.

In the circuit shown in Fig. initially key K₁ is closed and key K₂ is open. Then K₁ is opened and K₂ is closed (order is important). [Take Q₁' and Q₂' as charges on C₁ and C₂ and V₁ and V₂ as voltage respectively.]

 

Then

In Davison-Germer experiment, an electron beam is incident on a crystal. The reflected beam consists of: