L.1 Electrical Circuits

Practice Worksheet — name: ______________________ date: ____________

Formulas for this topic

Ohm's Law

V = IR

Electrical Power

P = VI

Resistors in Series

R_{total} = R_1 + R_2 + \dots

Resistors in Parallel

\frac{1}{R_{total}} = \frac{1}{R_1} + \frac{1}{R_2} + \dots

Section A — Multiple choice

A1. If a potential difference of 12 V is applied across a 4 Ohm resistor, what is the current?

A $3\, A$
B $8\, A$
C $16\, A$
D $48\, A$

A2. In a series circuit, how behaves the current at different points?

A It divides among the components
B It is the same at all points
C It increases with each resistor
D It drops to zero after the first component

Section B — Short answer

B1. Describe the difference between series and parallel circuits regarding potential difference.

B2. State Ohm's Law and explain its limitations.

Answer key

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Section A

A1: $3\, A$

A2: It is the same at all points

Section B

B1: In a series circuit, the total voltage of the source is split among the components. In a parallel circuit, each branch experiences the full potential difference of the source.

B2: Ohm's Law states that the current through a conductor is directly proportional to the potential difference across it, provided temperature and other physical conditions remain constant. It does not apply to non-ohmic components like filament lamps.