Physics - Electricity: Circuits and Symbols

Grade 7IGCSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

•

I

•

V

•

R

•

A

•

I_1 = I_2 = I_3

•

V_1 = V_2

📐Formulae

V = I \times R

I = \frac{V}{R}

R = \frac{V}{I}

R_{total} = R_1 + R_2 + R_3... \text{ (for series circuits)}

💡Examples

Problem 1:

9V

Solution:

R = \frac{V}{I} = \frac{9V}{0.5A} = 18\Omega

Explanation:

R = \frac{V}{I}

Problem 2:

R_1 = 4\Omega

Solution:

R_{total} = R_1 + R_2 = 4\Omega + 6\Omega = 10\Omega

Explanation:

In a series circuit, the total resistance is the sum of all individual resistances along the path.

Problem 3:

20\Omega

Solution:

I = \frac{V}{R} = \frac{240V}{20\Omega} = 12A

Explanation:

I = \frac{V}{R}