Ohm’s Law

1. 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

2. 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

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

4. 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

5. 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

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

7. 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

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

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

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