Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

Two files lines can ____.

A ball kept in a closed box moves in the box making collisions with the walls. The box is kept on a smooth surface. The velocity of the centre of mass:

1. Of the box remains constant.
2. Of the box plus the ball system remains constant.
3. Of the ball remains constant.
4. Of the ball relative to the box remains constant.

If M is the atomic mass and A is the mass number, packing fraction is given by

(a)

(b)

(c)

(d)

A charged conducting sphere does not produce an electric field:

The current in a LR circuit builds up to  th of its steady state value in 4s. The time constant of this circuit is

(a)

(b)

(c)

(d)

A coil resistance 20W and inductance 5H is connected with a 100V battery. Energy stored in the coil will be

(a) 41.5 J

(b) 62.50 J

(c) 125 J

(d) 250 J

A resistor of resistance R is connected to an ideal battery. If the value of R is decreased, the power dissipated in the resistor will:

de-Broglie wavelength is :

Which of the following quantities do not depend on the choice of zero potential or zero potential energy?

Three capacitors of capacitances 3 μF, 9μF  and 18 μF  are connected once in series and another time in parallel. The ratio of equivalent capacitance in the two cases will be

(a) 1 : 15

(b) 15 : 1

(c) 1 : 1

(d) 1 : 3