Class XII Physics Semiconductors 5

If base current changes from 50μA to 70μA and the current gain is 200. What is the percentage change in the output voltage of the amplifier if Vcc= 15V and Rc=1kΩ?

In given amplifier, collector resistance is 6kΩ. Voltage and current gain are 25 and 100 respectively. Rin is 2.4kΩ. Find the load resistance.

Find R_b such that the transistor can be used as a switch which is open. V_BE = 0.7V

Initial LC oscillator frequency is 150Hz and inductance L=3H. If frequency is changed to 180Hz without changing the inductance, find the percentage change in capacitance of the circuit.

Feedback fraction = 0.6 and open loop voltage gain is 50. If input voltage id 5V, find the output voltage.

Statement 1: A transistor cannot be used as a rectifier.
Statement 2: Either the emitter – base or the base- collector alone can be used as rectifier.
Reason: Base is thin and lightly doped.

The ratio of change in collector current to corresponding change in base-emitter voltage depends upon

What fraction of tetravalent atom must be replaced with pentavalent atom so as to increase its number density of about by a factor of 10000.(density of tetravalent is 2.33 g/cm³ ,molar mass is 28.1 g/mol, density of pentavalent is 4.28 g/cm³ ,molar mass is 17.3 g/mol)