Electricity

Question 1

What causes a current to flow?

Answer 1

For electrical charge to flow through a closed circuit the circuit must include a source of potential difference (voltage).

Question 2

What is an electric current?

Answer 2

Electric current is a flow of electrical charge (specifically electrons with a negative charge in metals). The size of the electric current is the rate of flow of electrical charge.

Question 3

How would we calculate the charge flowing through a circuit?

Answer 3

Charge flow = Current × time

Q = It

Charge (Coulombs, C), Current (Amps, A), Time (Seconds, s)

Question 4

What is the current in a circuit

dependent on?

Answer 4

The current (I) through a component depends on both the resistance (R) of the component and the potential difference (V) across the component.

Question 5

How would we calculate the
current flowing in a circuit?

Answer 5

Current = Potential difference / Resistance

I = V /R

Current (Amps, A), Potential difference (Volts, V), Resistance (Ohms, Ω)

Question 6

Voltage, current and resistance in a series circuit

Answer 6

Voltage is shared between components
Current is the same everywhere
Total Resistance is the sum of the resistances of each component