### GATE 1998 ECE Video Solutions on EDC (Electronic Devices and Circuits)

1. The electron and hole concentrations in a intrinsic semiconductor are ni and pi respectively. When doped with a P-type material, these changes to n and p respectively. Then
a. n + P = ni + Pi
b. n + ni = p + pi
c. npi = nip
d. np = nipi

2. The static characteristic of an adequately forward biased PN junction is a straight line, if the plot is of
a. Log I vs. log V
b. Log I vs. V
c. I vs. log V
d. I vs. V

3. A long specimen of p-type semiconductor material
a. Is positively charged
b. Is electrically neutral
c. Has an electric field directed along its length
d. Acts as a dipole

4. Two identical FETs, each characterized by the parameters gm and rd are connected in parallel. The composite FET is then characterized by the parameters
a. gm/2 and 2rd
b. gm/2 and rd/2
c. 2gm and rd/2
d. 2gm and 2rd

5. The units of (q/KT) are
a. V
b. V-1
c. J
d. J/K

6. The threshold voltage for each transistor in figure is 2 volts.i must take the values
For this circuit to work as an inverter, V
a. -5 volts and 0 volts
b. -5 volts and 5 volts
c. 0 volts and 3 volts
d. 3 volts and 5 volts

7.. The JFET in the circuit of figure is characterized by the parameters IDSS = 4 mA and Vp = -4 volts. Find (a) Vo if Vi = 0 and (b) Vi if Vo = 0 