Which quantity consists of a unit 1KWh ?

A. Energy
B. Time
C. Power
D. Charge

1 kWh is the amount of energy used by a 1 kW (1000 watt) resistance for 1 hour. Energy = Power × Time.

Which quantity should be measured by the voltmeter ?

A. Current
B. Voltage
C. Power
D. Speed

Voltmeter is a high resistance device used for measuring potential difference or voltage. It must be connected in parallel for measurement

Internal resistance of ideal current source is ?

A. zero
B. infinite
C. finite
B. 100 ohms

Ideal current source delivers energy at specified current, which is independent on voltage across the load. The internal resistance must become very high to deliver maximum current.

Internal resistance of ideal voltage source is ?

A. zero
B. infinite
C. finite
D. 100 ohms

Internal resistance of ideal voltage source is

Capacitor does not allow the sudden change of ?

A. current
B. voltage
C. power
D. None of the above

The expression of current through a capacitor is
For sudden change of voltage infinite current is required. But practically it is not possible.
Practical capacitor circuit has finite value of time constant

Inductor does not allow the sudden change of

A. current
B. voltage
C. power
D. None of the above

Voltage developed across an inductor is expressed bY
Sudden change of current means di will change at dt → 0 (dt tends to zero), so sudden change of current means infinite voltage. Therefore it is not possible.

Power dissipation in ideal inductor is

A. Maximum
B. Minimum
C. Zero
D. A finite value

Internal resistance of ideal inductor is zero. As there is no resistance, there should not be any dissipation of power. Pure inductor has no resistive component, so it active power dissipation is zero.

Which of the following are the passive elements?

A. Resistor
B. Bulb
C. Both
D. None of these.

When the element is not capable of delivering energy independently, are called as passive element. Both resistor and bulb are the passive elements and they can’t increase the energy level of a circuit

If 1 A current flows in a circuit, the number of electrons flowing through this circuit is

A. 0.625 × 1019
B. 1.6 × 1019
C. 1.6 × 10-19
D. 0.625 × 10-19

The charge of one electron is 1.6 × 10 – 19 coulomb. Again 1 A current means transferring of 1 coulomb charge per one second.

The resistivity of the conductor depends on

A. area of the conductor.
B. length of the conductor.
C. type of material.
D. none of these.

The resistivity is a property of material, defined as the resistance between two opposite faces of a cube of a material of unit volume. That is why resistivity is only the unique property of material and it does not depend upon the dimension of any piece of material.