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

If an observer is moving with respect to a stationary electron, then he observes

(a) Only magnetic field

(b) Only electric field

(c) Both (a) and (b)

(d) None of the above

Consider a mixture of oxygen and hydrogen kept at room temperature. AB compared to a hydrogen molecule an oxygen molecule hits the wall:

1. With greater average speed.
2. With smaller average speed.
3. With greater average kinetic energy.
4. With smaller average kinetic energy.

An inflated balloon was pressed against a wall after it has been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. What force might be responsible for the attraction between the balloon and the wall?

When current is passed in antimony-bismuth couple, then

(a) The junction becomes hot when the current is from bismuth to antimony

(b) The junction becomes hot when current flows from antimony to bismuth

(c) Both junctions become hot

(d) Both junctions become cold

The breakdown in a reverse biased p-n junction diode is more likely to occur due to:

An oscillator is nothing but an amplifier with

(a) Positive feed back	(b) Large gain
(c) No feedback	(d) Negative feedback

A dielectric slab is inserted between the plates of an isolated charged capacitor. Which of the following quantities will remain the same?

What is the S.I. unit of electric potential? 

What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength 6000   is used and slit width is 12 

(a) 2 rad

(b) 3 rad

(c) 1 rad

(d) 8 rad

The relative permeability of a material is 0.9. The material is: