ELECTRICAL DC CIRCUITS OBJECTIVE QUESTIONS WITH ANSWERS 3

ELECTRICAL DC CIRCUITS OBJECTIVE QUESTIONS WITH ANSWERS:

[1] Suppose Double the voltage in a simple dc circuit and cut the resistance in half , then the current will

A. Become four times as great

B. Become twice as great

C. Stay the same as it was before

D. Become half as great

Ans: A

[2] If four resistors are connected in series, each with a value of 4Kohm, the total resistance is

A. 1kΩ

B. 4 kΩ

C. 8 kΩ

D. 16 kΩ

Ans: D

[3] Three resistors each with a value of 0.069M ohm are in parallel. The total resistance is

A. 23 Ω

B. 23 KΩ

C. 204 Ω

D. 0.2 mΩ

Ans:B

[4] Proper biasing in an amplifier circuit

A. Causes it to oscillate

B. Prevents an impedance match

C. Can be obtained using a voltage divider network

D. Maximizes current flow

Ans: C

[5] A transistor can be protected from needless overheating by

A. A current-limiting resistor

B. Bleeder resistors

C. Maximizing the drive

D. Shorting out the power supply when the circuit is off

Ans: C

[6] A bleeder resistor

A. Is connected across the capacitor in a power supply

B. Keeps a transistor from drawing too much current

C. Prevents an amplifier from being over driven

D. Optimizes the efficiency of an amplifier

Ans: B

[7] An advantage of rheostat over a potentiometer is

A. Rheostat can handle higher frequencies

B. Rheostat is more precise

C. Rheostat can handle more current

D. Rheostat works better with dc

Ans: A

[8] The average power delivered to an impedance (4 - j3)Ω  by a current 5cos(100πt + 100π)A is [GATE 2012]

       a.  44.2W

       b.  50W

       c.  62.5W

       d. 125W

Ans: B

 

[9] A periodic voltage waveform observed on an oscilloscope across a load is shown. A permanent magnet moving coil (PMMC) meter connected across the same load reads [GATE 2012]

   a. 4 V

   b. 5 V

   c. 8 V

   d. 10 V

Ans: A

[10]The bridge method commonly used for finding mutual inductance is [GATE 2012]

    a. Heaviside Campbell bridge

    b. Schering bridge

    c. De Sauty bridge

    d. Wien bridge

Ans: A Solution Hint: Heaviside-campbell equal ratio bridge is used for measuring self-inductance in terms of mutural inductance. Schering bridge = used for measuring capacitance and dielectric loss of a capacitor. De Sauty bridge = used for comparing the capacitances of two capacitors. Wien bridge = used for audio-frequency measurement of capacitors over a wide range.