Network Theory Questions and Answers – Ohm’s Law

This set of Network Theory Multiple Choice Questions & Answers (MCQs) focuses on “Ohm’s Law”.

1. Resistance of a wire is yΩ. The wire is stretched to triple its length, then the resistance becomes ___________
a) y/3
b) 3y
c) 6y
d) y/6
View Answer

Answer: b
Explanation: Resistance of a conductor is directly proportional to its length. That is, when the length of conductor is tripled, its resistance also gets tripled.

2. An electric current of 10 A is the same as ___________
a) 10 J/C
b) 10 V/C
c) 10C/sec
d) 10 W/sec
View Answer

Answer: c
Explanation: Mathematically, electric current can be defined as the ratio of the charge to the time in which charge flows.

3. Consider a circuit with two unequal resistances in parallel, then ___________
a) large current flows in large resistor
b) current is same in both
c) potential difference across each is same
d) smaller resistance has smaller conductance
View Answer

Answer: c
Explanation: In parallel combination of resistors, the potential difference across each resistors is the same.
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4. In which of the following cases is Ohm’s law not applicable?
a) Electrolytes
b) Arc lamps
c) Insulators
d) Vacuum ratio values
View Answer

Answer: c
Explanation: According to Ohm’s law, it is applicable only to conductors. Hence, Ohm’s law is not applicable in case of insulators.

5. A copper wire of length l and diameter d has potential difference V applied at its two ends. The drift velocity is V. If the diameter of wire is made d/4, then drift velocity becomes ___________
a) V/16
b) 16V
c) V
d) V/4
View Answer

Answer: b
Explanation: Drift velocity is inversely propotional to area of material i.e, V=I/nAq.
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6. Which of the following bulbs will have high resistance?
a) 220V, 60W
b) 220V,100W
c) 115V,60W
d) 115V,100 W
View Answer

Answer: a
Explanation: Resistance is directly proportional to square of voltage and inversely proportional to the power.

7. Ohm’s law is not applicable to ___________
a) dc circuits
b) high currents
c) small resistors
d) semi-conductors
View Answer

Answer: d
Explanation: Ohm’s law is not applicable to semi-conductors and insulators.
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8. Conductance is expressed in terms of ___________
a) mho
b) mho/m
c) ohm/m
d) m/ohm
View Answer

Answer: a
Explanation: Conductance is the reciprocal of resistance and is expressed in terms of mho.

9. Resistivity of a wire depends on ___________
a) length of wire
b) cross section area
c) material
d) all of the mentioned
View Answer

Answer: c
Explanation: Resistivity of a wire is a constant and it depends on the type of material used.
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10. In a current-voltage relationship graph of a linear resistor, the slope of the graph will indicate ___________
a) conductance
b) resistance
c) resistivity
d) a constant
View Answer

Answer: a
Explanation: The slope of the graph is the ratio of current to a voltage which indicates conductance.

Sanfoundry Global Education & Learning Series – Network Theory.

To practice all areas of Network Theory, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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