A 2V battery is connected across AB as shown in the figure. The value of the current supplied by the battery when in one case battery’s positive terminal is connected to A and in other case when positive terminal of battery is connected to B will respectively be :
0.2 A and 0.1 A
0.4 A and 0.2 A
0.1 A and 0.2 A
0.2 A and 0.4 A
In the following, which one of the diodes is reverse biased?
Given : A and B are input terminals.
Logic 1 = > 5 V
Logic 0 = < 1 V
Which logic gate operation, the following circuit does ?
For LED’s to emit light in visible region of electromagnetic light, it should have energy band gap in the range of :
0.1 eV to 0.4 eV
0.5 eV to 0.8 eV
0.9 eV to 1.6 eV
1.7 eV to 3.0 eV
An n-p-n transistor has three leads A, B and C. Connecting B and C by moist fingers, A to the positive lead of an ammeter, and C to the negative lead of the ammeter, one finds large deflection. Then, A, B and C refer respectively to :
Emitter, base and collector
Base, emitter and collector
Base, collector and emitter
Collector, emitter and base.
For a common emitter configuration, if α and β have their usual meanings, the incorrect relationship between α and β is :
Carbon, silicon and germanium have four valence electrons each. At room temperature which one of the following statements is most appropriate ?
The number of free electrons for conduction is significant only in Si and Ge but small in C.
The number of free conduction electrons is significant in C but small in Si and Ge .
The number of free conduction electrons is negligibly small in all the three.
The number of free electrons for conduction is significant in all the three .
A junction shown in the figure can act as a rectifier.
An alternating current source is connected in the circuit. The current in the resistor can be shown by
The reverse biasing in a PN junction diode
Decreases the potential barrier
Increases the potential barrier
Increases the number of minority charge carriers
Increases the number of majority charge carriers
The approximate ratio of resistances in the forward and reverse bias of the PN-junction diode is
PN-junction diode works as an insulator, if connected
In forward bias
In reverse bias
None of these
On increasing the reverse bias to a large value in a PN-junction diode, current.
Which of the following statements concerning the depletion zone of an unbiased PN junction is (are) true
The width of the zone is independent of the densities of the dopants (impurities)
The width of the zone is dependent on the densities of the dopants
The electric field in the zone is produced by the ionized dopant atoms
The electric field in the zone is provided by the electrons in the conduction band and the holes in the valence band
When a PN junction diode is reverse biased
Electrons and holes are attracted towards each other and move towards the depletion region
Electrons and holes move away from the junction depletion region
Height of the potential barrier decreases
No change in the current takes place
What is the current in the circuit shown below
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
In the circuit (1) and (2)
In the circuit (2) and (3)
In the circuit (1) and (3)
Only in the circuit (1)
The PN junction diode is used as
The following truth table corresponds to the logic gate
A 0 0 1 1
B 0 1 0 1
X 0 1 1 0
The electrical resistance of depletion layer is large because
It has no charge carriers
It has a large number of charge carriers
It contains electrons as charge carriers
It has holes as charge carriers
The electrical circuit used to get smooth dc output from a rectifier circuit is called