Two PN-junctions can be connected in series by three different methods as shown in the figure. If the potential difference in the junctions is the same, then the correct connections will be
(a) In the circuit (1) and (2) (b) In the circuit (2) and (3)
(c) In the circuit (1) and (3) (d) Only in the circuit (1)
On increasing the reverse bias to a large value in a PN-junction diode, current
(1) Increases slowly
(2) Remains fixed
(3) Suddenly increases
(4) Decreases slowly
A semiconductor device is connected in a series circuit with a battery and a resistance. A current is found to pass through the circuit. If the polarity of the battery is reversed, the current drops almost to zero. The device may be
(1) A P-type semiconductor
(2) An N-type semiconductor
(3) A PN-junction
(4) An intrinsic semiconductor
In a junction diode, the holes are due to
(1) Protons
(2) Neutrons
(3) Extra electrons
(4) Missing of electrons
The cause of the potential barrier in a P-N diode is
(1) Depletion of positive charges near the junction
(2) Concentration of positive charges near the junction
(3) Depletion of negative charges near the junction
(4) Concentration of positive and negative charges near the junction
1. | the potential is the same everywhere. |
2. | the \(\mathrm{p}\text-\)type is at higher potential than the \(\mathrm{n}\text-\)type side. |
3. | there is an electric field at the junction directed from the \(\mathrm{n}\text-\)type side to the \(\mathrm{p}\text-\)type side. |
4. | there is an electric field at the junction directed from the \(\mathrm{p}\text-\)type side to the \(\mathrm{n}\text-\)type side. |
Which of the following statements is not true
(1) The resistance of intrinsic semiconductors decrease with increase of temperature
(2) Doping pure with trivalent impurities give P-type semiconductors
(3) The majority carriers in N-type semiconductors are holes
(4) A PN-junction can act as a semiconductor diode
The dominant mechanisms for motion of charge carriers in forward and reverse biased silicon P-N junctions are
(1) Drift in forward bias, diffusion in reverse bias
(2) Diffusion in forward bias, drift in reverse bias
(3) Diffusion in both forward and reverse bias
(4) Drift in both forward and reverse bias
1. | \(V_B\) increases, \(x\) decreases | 2. | \(V_B\) decreases, \(x\) increases |
3. | \(V_B\) increases, \(x\) increases | 4. | \(V_B\) decreases, \(x\) decreases |
When the P end of P-N junction is connected to the negative terminal of the battery and the N end to the positive terminal of the battery, then the P-N junction behaves like
(1) A conductor
(2) An insulator
(3) A super-conductor
(4) A semi-conductor