Q1.The cross section of a JFET is shown in the following figure. Let Vc be -2
V and let VP be the initial pinch -off voltage. If the width W is doubled (with
other geometrical parameters and doping levels remaining the same), then the
ratio between the mutual trans conductances of the initial and the modified
JFET is
Q3.Consider the Schmidt trigger circuit shown below
A triangular wave which goes from -12 to 12 V is applied to the inverting input
of OPMAP. Assume that the output of the OPAMP swings from +15 V to -15 V.
The voltage at the non-inverting input switches between
Answer : Option CExplaination / Solution:
Let the voltage at non inverting terminal be V1, then after applying KCL at non
inverting terminal side we have
If V0 swings from -15 to +15 V then V1 swings between -5 V to +5 V.
Q4.Consider the following assertions.
S1 : For Zener effect to occur, a very abrupt junction is required.
S2 : For quantum tunneling to occur, a very narrow energy barrier is required.
Which of the following is correct ?
Answer : Option AExplaination / Solution: No Explaination.
The logic function implemented by the following circuit at the terminal OUT is
Answer : Option DExplaination / Solution:
From the figure shown below it may be easily seen upper MOSFET are shorted
and connected to Vdd thus OUT is 1 only when the node S is 0,
Since the lower MOSFETs are shorted to ground, node S is 0 only when input P
and Q are 1. This is the function of AND gate.
Q7.One end of a loss-less transmission line having the characteristic impedance of 75Ω and length of 1 cm is short-circuited. At 3 GHz, the input impedance at the other end of transmission line is