Electronics

Very short answer questions (1 Mark)

1. Write the relation between number density of holes and number density of free electrons in an intrinsic semiconductor.
2. Write the value of resistance offered by an ideal diode when (i) forward based (ii) reverse biased.
3. Write any one use of (i) photodiode (ii) LED.
4. Write the truth table for a two input AND gate.
5. At what temperature does a semiconductor behave as an insulator?
6. Write two uses of logic gates in daily life.
7. If L and C are the inductance and capacitance of the tank circuit of an oscillator, what will be the frequency of oscillation?
8. Semiconductors do not support strong current i.e., a semiconductor is damaged when strong current passes through it. Why?
9. Draw I-V characteristic of a solar cell.
10. What is the phase difference between input and output waveform in the common emitter transistor amplifier?
11. What type of feedback is required in an oscillator? Why?
12. What is the direction of diffusion current in a junction diode?
13. Draw a circuit diagram showing the biasing of a photodiode.
14. Name the semiconductor device that can be used to regulate an unregulated dc power supply.
15. Name the p.n. junction diode which emits spontaneous radiation when forward biased.
16. Name any one semiconductor used to make LED.
17. What is meant by ‘regulation’ as applied to a power supply?
18. A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. When polarity of the battery is reversed, the current drops to almost zero. Name the semiconductor device.