Current electricity

1. The thickness of insulation provided on the conductor depends on

The magnitude of voltage on the conductor
The magnitude of current flowing through it
Both (A) and (B)
None of the above

Detailed SolutionThe thickness of insulation provided on the conductor depends on

2. Switching of a lamp in house produces noise in the radio. This is because switching operation produces

Arcs across separating contacts
Mechanical noise of high intensity
Both mechanical noise and arc between contacts
None of the above

Detailed SolutionSwitching of a lamp in house produces noise in the radio. This is because switching operation produces

3. When electric current passes through a metallic conductor, its temperature rises. This is due to

Collisions between conduction electrons and atoms
The release of conduction electrons from parent atoms
Mutual collisions between metal atoms
Mutual collisions between conducting electrons

Detailed SolutionWhen electric current passes through a metallic conductor, its temperature rises. This is due to

4. Nichrome wire is an alloy of

Lead and zinc
Chromium and vanadium
Nickel and chromium
Copper and silver

Detailed SolutionNichrome wire is an alloy of

5. Three 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners?

$$ rac{3}{2}Omega $$
6 $$Omega $$
4 $$Omega $$
$$ rac{8}{3}Omega $$

Detailed SolutionThree 6 ohm resistors are connected to form a triangle. What is the resistance between any two corners?

6. The number of electrons in the outer most orbit of carbon atom is

3
4
6
7

Detailed SolutionThe number of electrons in the outer most orbit of carbon atom is

7. Ohm’s law is not applicable to

Semiconductors
D.
circuits C. Small resistors
High currents

Detailed SolutionOhm’s law is not applicable to

8. With three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals

10 W
20 W
40 W
60 W

Detailed SolutionWith three resistances connected in parallel, if each dissipates 20 W the total power supplied by the voltage source equals

9. Conductance is reciprocal of

Resistance
Inductance
Reluctance
Capacitance

Detailed SolutionConductance is reciprocal of

10. Which of the following materials has a negative temperature coefficient of resistance?

Copper
Aluminum
Carbon
Brass

Detailed SolutionWhich of the following materials has a negative temperature coefficient of resistance?

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