Basics of Circuits
What is the formula for potential difference (p.d.)?
Answer: V = W/Q.
What happens when a force acts on a moving charge in a circuit?
Work is done, and energy is transferred.
What is the formula for resistors in series?
R_total = R₁ + R₂ + R₃
What is the formula for electrical power?
P=VI
What is the unit of potential difference?
Volt (V)
How is chemical energy converted in a cell?
Into electrical potential energy.
What is the formula for resistors in parallel?
1/R_total = 1/R₁ + 1/R₂ + 1/R₃
Rearrange the power formula to express it in terms of resistance (R).
P = I²R or P = V²/R
What term describes the energy per unit charge provided by a cell?
Electromotive force (e.m.f.).
Why do electrons lose energy in a circuit?
Due to collisions with atoms or ions.
Calculate the total resistance of 60 strands of wire, each with 3 Ω resistance (parallel combination)
0.05 Ω
A device operates at 10 A with a potential difference of 5 V. What is the power consumed?
50 W
True or False: Electrons carry energy from the cell to a circuit component.
False; energy is transferred through the motion of charge carriers.
Compare the energy transfer in a circuit to a bike chain.
The chain doesn't carry energy; its motion allows energy transfer, similar to charge carriers in a circuit.
What is the total resistance of three resistors (2 Ω, 4 Ω, 6 Ω) in parallel?
1.09 Ω
What is 1 watt equivalent to?
1 joule per second.