SSC · Analog and Digital Electronics practice

Correct answer: C

Silicon starts conducting at about 0.6 to 0.7 V and germanium at about 0.2 to 0.3 V.

Correct answer: C

In breakdown the voltage across the Zener remains nearly constant over a wide range of current.

Correct answer: D

β = α/(1 − α) = 0.98 / 0.02 = 49.

Correct answer: C

In cut-off it is OFF (open) and in saturation it is ON (closed) with a small voltage drop.

Correct answer: B

13 = 8 + 4 + 1 = 1101 in binary.

Correct answer: C

NAND is the complement of AND, and AND is HIGH only when all inputs are HIGH.

Correct answer: C

Gain = −Rf/Rin = −100/10 = −10.

Correct answer: A

Both half cycles of the input produce output pulses, so the ripple frequency is twice the supply frequency.

Correct answer: A

A half-wave rectifier has a ripple factor of 1.21 and a full-wave rectifier 0.482.

Correct answer: D

IB = (10.7 − 0.7)/470 kΩ = 21.3 μA. IC = β IB = 100 × 21.3 μA = 2.13 mA.

Correct answer: A

An ideal op-amp has infinite gain and input impedance, and zero output impedance.

Correct answer: D

Gain = 1 + Rf/R1 = 1 + 9 = 10.

Correct answer: A

5 = 0101. Invert to get 1010 and add 1 to get 1011.

Correct answer: D

With both inputs high the output complements on each clock pulse, which is the basis of counters.

Correct answer: C

Ten states need ⌈log₂ 10⌉ = 4 flip-flops, and the counter is reset at count 10.

Correct answer: D

A + A′B = (A + A′)(A + B) = A + B.

Correct answer: C

59 in binary is 111011.

Correct answer: C

Vdc = 2Vm/π = 15.28 V.

Correct answer: A

IC = β IB = 80 × 30 μA = 2.4 mA.

Correct answer: C

1 in decimal is 1.