Group I lists four different semiconductor devices. match each device in Group I with its charactecteristic property in Group II
Group-I Group-II
(P) BJT (1) Population iniversion
(Q) MOS capacitor (2) Pinch-off voltage
(R) LASER diode (3) Early effect
(S) JFET (4) Flat-band voltage
Answer : Option CExplaination / Solution:
In BJT as the B-C reverse bias voltage increases, the B-C space charge region
width increases which xB (i.e. neutral base width) > A change in neutral base
width will change the collector current. A reduction in base width will causes
the gradient in minority carrier concentration to increase, which in turn causes
an increased in the diffusion current. This effect si known as base modulation as
early effect.
In JFET the gate to source voltage that must be applied to achieve pinch off
voltage is described as pinch off voltage and is also called as turn voltage or
threshold voltage.
In LASER population inversion occurs on the condition when concentration of
electrons in one energy state is greater than that in lower energy state, i.e. a non
equilibrium condition.
In MOS capacitor, flat band voltage is the gate voltage that must be applied to
create flat ban condition in which there is no space charge region in semiconductor
under oxide.
Q9.A lossy capacitor Cx, rated for operation at 5 kV, 50 Hz is represented by an
equivalent circuit with an ideal capacitor Cp in parallel with a resistor Rp. The
value Cp is found to be 0.102 µF and the value of Rp = 1.25 MΩ . Then the power
loss and tan ∂ of the lossy capacitor operating at the rated voltage, respectively,
Answer : Option CExplaination / Solution: No Explaination.