# Network Theory Questions and Answers – Ohm’s Law

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

1. Which of the following bulbs will have high resistance?
a) 220V, 60W
b) 220V,100W
c) 115V,60W
d) 115V,100 W

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

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

Explanation: Semiconductors and insulators are exempt from Ohm’s law.

3. Conductance is expressed in terms of ___________
a) mho
b) mho/m
c) ohm/m
d) m/ohm

Explanation: The reciprocal of resistance is conductance, which is measured in mho.

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

Explanation: A wire’s resistivity is a constant that is determined by the type of materials.

5. 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

Explanation: The slope of the graph represents the current-to-voltage ratio, which represents conductance.

6. 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

Explanation: A conductor’s resistance is directly proportionate to its length. That is, if the length of a conductor is tripled, the resistance of the conductor is also tripled.

7. 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

Explanation: Electric current can be defined mathematically as the ratio of the charge to the time it takes for the charge to flow.

8. 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

Explanation: The potential difference between each resistor in a parallel set of resistors is the same.

9. In which of the following cases is Ohm’s law not applicable?
a) Electrolytes
b) Arc lamps
c) Insulators
d) Vacuum ratio values

Explanation: It only applies to conductors, according to Ohm’s law. As a result, Ohm’s law does not apply to insulators.

10. 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

Explanation: Drift velocity is inversely propotional to area of material i.e, V=I/nAq.

According to Ohm’s law, the current flowing through a conductor between two places is proportional to the voltage across the conductor. When the proportionality constant, resistance, is included, the conventional mathematical equation that expresses this initially caused. where I denotes the current through the conductor in amperes, V signifies the voltage measured across the conductor in volts, and R is the conductor’s resistance in ohms. Ohm’s law indicates that the R in this relationship remains constant irrespective of the current.