Electrical DC Circuits Objective Questions: Part-10

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 mutual 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. 

[11] An ideal voltage source will charge an ideal capacitor[Gate 1997]

(a) In infinite time
(b) Exponentially
(c) Instantaneously
(d) None of the above

Ans:C

[12] A practical current source is usually represented by[Gate 1997]
(a) A resistance in series with an ideal current source
(b) A resistance in parallel with an ideal current source
(c) A resistance in parallel with an ideal voltage source
(d) None of the above

Ans: B

[13] Energy stored in a capacitor over a cycle, when excited by an ac source is[Gate 1997]
(a) The same as that due to a dc source of equivalent magnitude
(b) Half of that due to a dc source of equivalent magnitude
(c) Zero
(d) None of the above

Ans: C

[14] A major advantage of the active filters is that they can be realized without using[Gate 1997]
(a) Opamps
(b) Inductors
(c) Resistors
(d) Capacitors

Ans: B

[15] The computer program which converts statements written in high level language to object code is  known as [Gate 1997]
(a) Assembler
(b) Operating system
(c) Object oriented software
(d) None of the above

Ans: A

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