This set of Electronic Devices and Circuits Multiple Choice Questions & Answers (MCQs) focuses on “The Volt Ampere Characteristics”.
1. The voltage equivalent of temperature (Vt) in a P-N junctions is given by.
a) T/1000 volts
b) T/300 volts
c) T/1600 volts
d) T/11600 volts
Explanation: We know that the P-N junction is temperature dependent, it varies with the change in temperature the measure of change that is the voltage equivalent of temperature is given by Vt = T/11600 volts.
2. At room temperature what will be voltage equivalent of temperature.
a) 10 mV
b) 4.576 mV
c) 26 mV
d) 98 V
Explanation: Room temperature is 27o C = 300 k .We know that Vt= T/11600 volts by substituting the value of T we get 300/11600 = 26mV.
3. In a P-N junction the positive voltage at which the diode starts to conduct consequently is called.
a) Cut off voltage
b) Saturation voltage
c) Knee voltage
d) Breakdown voltage
Explanation: At a certain critical voltage, a large reverse current flows and the diode is said to be in breakdown region, at this region the diode will be forward biased and starts to conduct consequently.
4. In volt ampere characteristics the current increases with voltage _________
Explanation: The current in the volt ampere characteristics increases exponentially with respect to voltage I(t) = eV(t).
5. The cut off voltage for diode of silicon semiconductor and germanium semiconductor is ____ volts.
a) 0.5 and 0.1
b) 0.7 and 0.3
c) 1 and 0.5
d) 0.5 and 1
Explanation: The cut off voltage is the voltage only after which the semiconductors conduct, the cut off voltage for silicon is 0.7V in the sense the silicon diode will conduct only when voltage is more than 0.7V and 0.3 for germanium.
6. What would be the current and voltage when there is no external voltage applied on the diode?
Explanation: When there is no external voltage applied on the circuit it acts as an open circuit and there will be no flow of charges hence the current and voltage will be zero.
7. In P-N junction V-I characteristics during forward biased, at what region the current increase is very low.
c) Cut off
Explanation: In the V-I characteristics the change in the current with respect to voltage is very less in depletion region due to the large resistance in the circuit as the resistance deceases by a certain value the current increases exponentially with voltage.
8. In a P-N junction diode during forward bias if the current increases more than the value that is rated will destroy the diode.
Explanation: If the current in the P-N junction diode during forward bias increases beyond the value rated on it will destroy the diode because voltage is directly proportional to current so extreme voltage will burn the diode down.
9. When the P-N junction diode is forward bias the current in circuit is controlled by.
a) External voltage
d) Internal voltage
Explanation: When the P-N junction is in forward bias that is the p side connected to the positive terminal of voltage source the current in the circuit can be varied by varying the resistance, the current flow decreases as the resistance increases and vice versa.
10. The P-N junction diode conducts in which direction.
a) Reverse direction
b) Forward direction
c) Both Forward and Reverse direction
d) Neither Forward nor Reverse direction
Explanation: The P-N junction diode conducts only in forward direction, it will not conduct in reverse direction so only Zener Diode was introduced as it conducts in both forward and reverse direction.
Sanfoundry Global Education & Learning Series – Electronic Devices and Circuits.
To practice all areas of Electronic Devices and Circuits, here is complete set of 1000+ Multiple Choice Questions and Answers.