Electronic Devices

1

The reading of the ammeter for a silicon diode in the given circuit is:

  1. 15 mA
  2. 11.5 mA
  3. 13.5 mA
  4. 0
2

In a common emitter amplifier circuit using an n-p-n transistor, the phase difference between the input and the output voltages will be:

  1. 180°
  2. 45°
  3. 90°
  4. 135°
3

The combination of gates shown below yields

  1. NAND gate
  2. NOT gate
  3. XOR gate
  4. OR gate
4

A strip of copper and another germanium are cooled from room temperature to 80 K. The resistance of

  1. each of these decreases
  2. each of these increases
  3. copper strip increases and that of germanium decreases
  4. copper strip decreases and that of germanium increases
5

In a transformer, number of turns in the primary coil are 140 and that in the secondary coil are 280. If current in primary coil is 4 A, then that in the secondary coil is

  1. 10 A
  2. 6 A
  3. 4 A
  4. 2 A
6

A diode detector is used to detect an amplitude modulated wave of 60% modulation by using a condenser of capacity 250 pico farad in parallel with a load resistance 100 kilo ohm. Find the maximum modulated frequency which could be detected by it.

  1. 10.62 KHz
  2. 5.31 MHz
  3. 5.31 KHz
  4. 10.62 MHz