BEE Analog and Digital Electronics 2

Question 1

In a common-emitter BJT amplifier, increasing the collector resistance RC while keeping other parameters fixed will:

Accepted Answer

Increase voltage gain

Answer

Voltage gain Av = -gm·RC, so increasing RC directly increases the magnitude of voltage gain.

Question 2

Which logic gate is equivalent to an AND gate followed by a NOT gate?

Accepted Answer

NAND

Answer

A NAND gate produces the complement of the AND operation, making it equivalent to AND followed by NOT.

Question 3

A Schmitt trigger is primarily used to:

Accepted Answer

Convert sine waves to square waves with hysteresis

Answer

A Schmitt trigger uses hysteresis (two threshold levels) to cleanly convert noisy analog signals into digital square waves.

Question 4

In a full-wave bridge rectifier with a peak input voltage of 20V and diode forward voltage drop of 0.7V each, the peak output voltage is:

Accepted Answer

18.6V

Answer

Two diodes conduct simultaneously in a bridge rectifier, so peak output = 20 - 2(0.7) = 18.6V.

Question 5

A D flip-flop differs from an SR flip-flop primarily because it:

Accepted Answer

Eliminates the forbidden state by tying S and R through an inverter

Answer

Connecting an inverter between the S and R inputs ensures S and R are always complements, eliminating the invalid S=R=1 state.

BEE - Bachelor of Electrical Engineering Practice Test