Circuit Diagrams

Question 1

Circuit Diagram Symbols

Answer 1

A cell is a source of energy for circuit (smallest unit). Multiple cells make a battery.

Question 2

Designing Series Circuit

Answer 2

Series circuits are electrical circuits in which the current can only flow along one path.

1. A power supply is always required.
2. If there is a break in the circuit, the entire circuit fails.
3. Cheap and Easy.
4. Kirchoff’s current law: all the current is same at all points.
5. Kirchoff’s voltage law -> sum of the potential difference across each component must equal the voltage supplied.

Question 3

Designing Parallel Circuits

Answer 3

In parallel circuits, current can flow along multiple paths.

1. A power supply is always required.
2. Any failure is confined to its local branch.
3. Components can be turned on or off independently.
4. Kirchoff’s current law -> current is divided amongst branches.
5. Kirchoff’s voltage law -> each branch receives the same voltage from source.

Question 4

Designing Combination Circuits

Answer 4

Series/parallel circuits are often called combination circuits, as they combine the features and properties of both.

1. Power supply needed
2. Parallel circuit is a part of a greater series circuit as shown.
3. Applying Kirchoff’s current and voltage laws is more difficult.

Question 5

Power Dissipation

Answer 5

Electrical Components are designed to only operate within a specific range of voltage and current. This means resistors are often used to regulate current and dissipate electrical power. This is normally achieved by converting electrical potential energy to heat. Since P = VI, and I = V/R. Substituing I for P = VI gives P=V^2/R.

Since V = IR, substituting for V in P = VI gives: P = I^2R. These two new questions allow us to calculate the power dissipated (P) by a resistor of resistance (R),

Question 6

Series Circuits

Answer 6

Current can only flow along one path. The current is constant throughout the circuit. The sum of the potential difference across equals to the voltage supplied by the power source. Ohm’s law can be applied to find the resistance of individual components.

Question 7

Parallel Circuits

Answer 7

Parallel Circuits are circuits in which current can flow along multiple paths. Current is divided between branches, according to the resistance of each branch. The potential difference across each branch is equal to the voltage supplied to the circuit. Ohm’s law can be applied to find the resistance of each branch.