Questions and answers for exam Preparation

MCQs

Total Questions : 227 | Page 3 of 23 pages

Question 21. The knee voltage of a diode is approximately equal to the

None of these
Applied voltage
Forward voltage
Barrier potential
Breakdown voltage

Discuss Question

Answer: Option D. -> Barrier potential

Question 22. Which one of the following is a direct statement of Ohm's law?

The algebraic sum of currents entering and leaving a point is equal to zero
The total resistance of a parallel circuit is less than the value of the smallest resistance
The algebraic sum of voltages in a loop is equal to zero
The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it
None of these

Discuss Question

Answer: Option D. -> The voltage drop across a resistance is proportional to the value of resistance and the amount of current flowing through it

Question 23. A high-pass filter:

increases the level of all frequencies by a significant amount
passes higher-frequency signals and reduces lower-frequency signals
None of these
has no effect on ac signals
passes lower-frequency signals and reduces higher-frequency signals

Discuss Question

Answer: Option B. -> passes higher-frequency signals and reduces lower-frequency signals

Question 24. The rms value of a sine waveform is:

None of these
equal to 1.41 times the peak amplitude
equal to 0.707 times the peak amplitude
the time required to complete one full cycle
the number of cycles completed in one second

Discuss Question

Answer: Option C. -> equal to 0.707 times the peak amplitude

Question 25. A zener regulator has an input voltage from 15 to 20 V and a load current from 5 to 20 mA. If the zener voltage is 6.8 V, what value should the series resistor have?

400 Ohm
550 Ohm
310 Ohm
None of these
410 Ohm

Discuss Question

Answer: Option E. -> 410 Ohm

Question 26. Which one of the following statements is true for the voltages in a series RC circuit?

The voltage always has the same amplitude and phase for every part of the circuit
The total voltage is less than the sum of the voltages across the resistance and capacitance
None of these
The total voltage is greater than the sum of the voltages across the resistance and capacitance
The total voltage is equal to the sum of the voltages across the resistance and capacitance

Discuss Question

Answer: Option B. -> The total voltage is less than the sum of the voltages across the resistance and capacitance

Question 27. The transistor has a collector current of 10 mA and a base current of 40 mA. What is the current gain of the transistor?