1
GATE ECE 1992
+2
-0.6
The 6 V Zener diode shown in figure has zero Zener resistance and a knee current of 5 mA. The minimum value of R, so that the voltage across it does not fall below 6 V is:
A
1.2 kΩ
B
50 Ω
C
80 Ω
D
0 Ω
2
GATE ECE 1991
+2
-0.6
The small signal capacitances of an abrupt P+−N junction is 1 nF at zero bias. If the built-in voltage is 1 volt, the capacitance at a reverse bias voltage of 99 volts is equal to
A
100
B
0.1
C
0.01
D
10
3
GATE ECE 1991
Numerical
+2
-0
Referring to the figure. The switch S is in position 1 initially and steady state conditions exist from time t = 0 to t = t0. At t = t0, the switch is suddenly thrown into position 2. The current I through the 10K resistor as a function of time t, from t = 0 is (in mA) _____________.

(Give the sketch showing the magnitudes of the current at t = 0, t = t0 and t = $$\infty$$ )

4
GATE ECE 1987
+2
-0.6
The diffusion capacitance of a P-N junction
A
Decreases with increasing current and increasing temperature
B
Decreases with decreasing current and increasing temperature
C
Increases with increasing current and increasing temperature
D
Does not depend on current and temperature
EXAM MAP
Medical
NEET