Basic Electronics :Part-3 Solved Objective Questions

[1] When the elements of an RLC circuit are both magnitude scaled and frequency scaled, which quality is unaffected?
A. Resistor
B. Resonant frequency
C. Bandwidth
D. Quality factor

Ans: D

[2] What kind of filter can be used to select a signal of one particular radio station?
A. Low pass
B. High pass
C. Band pass
D. Band stop

Ans: C

[3] A voltage source supplied a signal of constant amplitude, from 0 to 40kHz, to an RC lowpass filter. The load resistor experiences the maximum voltage at
A. DC
B. 10 kHz
C. 20 kHz
D. 40 kHz

Ans: A

[4] The most commonly used amplifier in sample & hold circuits is 
A. A unity gain non-inverting amplifier

B. A unity gain inverting amplifier

C. An inverting amplifier with a gain of 10

D. An inverting amplifier with a gain of 100

Ans: B

[5] Three identical amplifiers with each one having a voltage gain of 50, input resistance of 1K & output resistance of 250,are cascaded. The open circuit voltage gain of combined amplifier is

A. 49dB

B. 51dB

C. 98dB

D. 102dB

Ans: C

[6] The cascade amplifier is a multistage configuration of

A. CC-CB

B. CE-CB

C. CB-CC

D. CE-CC

Ans: B

[7] The current gain of a BJT is

A. g_mr₀

B. g_m/r₀

C. g_mr_π

D. g_m/r_π

Ans: C

[8] Introducing a resistor in the emitter of a common amplifier stabilizes the dc operating point against variations in

A. Only the temperature

B. Only the β of the transistor

C. Both Temperature & β

D. None of the above

Ans: C

[9] Voltage Series feedback (also called series-shunt feedback) results in

A. Increase in both input & output impedences

B. Decrease in both input & output impedences

C. Increase in input impedence & decrease in output impedence

D. Decrease in input impedence & increase in output impedence

Ans: C

[10] An amplifier without feedback has a voltage gain of a 50,input resistance of 1K & Output resistance of 2.5K. The input resistance of the current-shunt negative feedback amplifier using the above amplifier with a feedback of 0.2 is
A. 1/11K
B. 1/5K
C. 5K
D. 11K

Ans: A