Charge in Circuits

A series of free GCSE/IGCSE Physics Notes and Lessons.

Charge and Current
The following diagram gives the formula for charge and current. Scroll down the page for more examples and solutions on how to use the formula.

 

In these lessons, we will
• Calculate the charge flow in a circuit.
• Describe what is meant by an electric current.
• Calculate charge from current or current from charge.

Electric charge is measured in Coulombs (C).
A current of 1 Ampere = 1 Coulomb of charge flowing per second.
The size of the electric current is the rate of flow of the electrical charge.
Q = I × t

Examples:

1. Given that the current is 0.3A, calculate the charge flowing in the circuit in 20 seconds.
2. 360 C of charge flows around a circuit in 400 s. Calculate the current in the circuit.

• Show Step-by-Step Solutions

Electric charge and current
Examples:

1. A current of 2A flows through a bulb for three minutes. Calculate the amount of charge that flows through the bulb in this time.
2. A charge of 5kC flows through a variable resistor in two minutes. Calculate the reading on the anmeter which is connected to the circuit.

Try out our new and fun Fraction Concoction Game.

Add and subtract fractions to make exciting fraction concoctions following a recipe. There are four levels of difficulty: Easy, medium, hard and insane. Practice the basics of fraction addition and subtraction or challenge yourself with the insane level.

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