Circuit 2

Question 1

What is meant by potential difference?

Answer 1

The energy transferred to the component or the work done on it by each coulomb of charge that passes through it

Measured in volts (V)

Question 2

What is the unit of potential difference?

Answer 2

Volt (V)

1 volt is equivalent to 1 joule per coulomb

Question 3

What does an ammeter measure?

Answer 3

The current through an electrical component

Measured in amperes (A) or milliamperes (mA)

Question 4

What does a voltmeter measure?

Answer 4

The potential difference (voltage) across a component

Connected in parallel with the component

Question 5

What is the relationship between energy transferred (E), charge (Q), and potential difference (V)?

Answer 5

V = E/Q

Where E is in joules (J) and Q is in coulombs (C)

Question 6

What is the formula for resistance?

Answer 6

R = V/I

Where R is resistance in ohms (Ω), V is potential difference in volts (V), and I is current in amperes (A)

Question 7

What is the unit of resistance?

Answer 7

Ohm (Ω)

1 ohm is defined as the resistance that allows a current of 1 ampere to flow with a potential difference of 1 volt

Question 8

What does Ohm’s law state?

Answer 8

The current through a resistor at constant temperature is directly proportional to the potential difference across the resistor

This relationship holds true for ohmic conductors

Question 9

True or False: Reversing the potential difference across a resistor changes the resistance.

Answer 9

False

The resistance remains the same regardless of the direction of the current

Question 10

How does resistance vary with the length of a wire?

Answer 10

Resistance increases with the length of the wire

Measured by plotting resistance against length

Question 11

If the current through a wire is 0.5 A and the potential difference is 4.0 V, what is the resistance?

Answer 11

8 Ω

Calculated using R = V/I

Question 12

Fill in the blank: The potential difference across a component is _______ when the charge passing through is 64 C and the energy transferred is 320 J.

Answer 12

50 V

Calculated using V = E/Q

Question 13

What happens to the current when resistance in a circuit increases while maintaining the same potential difference?

Answer 13

The current decreases

This is due to the inverse relationship between resistance and current

Question 14

What do current-potential difference graphs illustrate for ohmic conductors?

Answer 14

A straight line through the origin

Indicates a constant resistance

Question 15

What happens to the resistance of a wire if the temperature is kept constant?

Answer 15

It remains constant

This is a characteristic of ohmic conductors

Question 16

Calculate the charge passing through a torch bulb when the current is 0.015 A for 1200 s.

Answer 16

18 C

Calculated using Q = I × t

Question 17

Calculate the energy delivered to the torch bulb when the current is 0.015 A and the potential difference is 12.0 V for 1200 s.

Answer 17

216 J

Calculated using E = V × Q