Electricity

Which quantity is measured in watts?

1. Resistance
2. Electric power
3. Current
4. Potential difference

If the resistance of a conductor is doubled while voltage remains constant, the current will:

1. Double
2. Become half
3. Remain unchanged
4. Become zero

The heating effect of electric current is explained by:

1. Joule's law of heating
2. Newton's law
3. Ohm's law only
4. Law of reflection

The commercial unit of electrical energy is:

1. Joule
2. Watt
3. Kilowatt-hour
4. Volt

In a parallel combination of resistors, the voltage across each resistor is:

1. Different
2. Same
3. Zero
4. Infinite

When resistors are connected in series, the total resistance is:

1. Less than individual resistance
2. Equal to the smallest resistance
3. Sum of all resistances
4. Zero

A device used to protect electrical circuits from excessive current is:

1. Motor
2. Fuse
3. Bulb
4. Battery

Electrical power is defined as:

1. Rate of doing electrical work
2. Total charge stored
3. Resistance of conductor
4. Amount of current only

The resistance of a conductor increases when:

1. Its length increases
2. Its area increases
3. Its thickness increases
4. It is made shorter

Which material is generally used for making electric wires?

1. Rubber
2. Copper
3. Wood
4. Plastic

The SI unit of electrical resistance is:

1. Ohm
2. Ampere
3. Volt
4. Joule

The resistance of a conductor depends on:

1. Length and area of cross-section
2. Colour only
3. Shape only
4. Temperature only

According to Ohm's law, the relationship between voltage, current, and resistance is:

1. V = IR
2. V = I/R
3. V = R/I
4. V = I + R

The potential difference between two points is measured using:

1. Ammeter
2. Voltmeter
3. Galvanometer
4. Rheostat

Why are household appliances connected in parallel rather than in series?

1. To reduce voltage across each appliance
2. To ensure each appliance receives the same voltage and operates independently
3. To increase resistance significantly
4. To prevent current flow

The electrical energy consumed by an appliance is given by:

1. Voltage × Resistance
2. Power × Time
3. Current × Resistance
4. Voltage ÷ Current

What is electric power?

1. Rate of doing electrical work
2. Total charge stored
3. Resistance of a conductor
4. Voltage only

What happens to the equivalent resistance when resistors are connected in parallel?

1. It becomes greater than the largest resistance
2. It remains unchanged
3. It becomes less than the smallest resistance
4. It becomes zero

Which combination of resistors provides the same current through all resistors?

1. Parallel combination
2. Series combination
3. Mixed combination
4. Open circuit

What is the SI unit of resistance?

1. Volt
2. Ampere
3. Ohm
4. Joule

According to Ohm's Law, current is directly proportional to:

1. Resistance
2. Length of conductor
3. Potential difference
4. Temperature

Which instrument is used to measure electric current?

1. Voltmeter
2. Ammeter
3. Galvanometer
4. Thermometer

What is electric current?

1. Flow of resistance
2. Flow of electric charge
3. Flow of voltage
4. Flow of energy only

What is the SI unit of electric current?

1. Volt
2. Ohm
3. Ampere
4. Watt