What is the actual direction of electron flow in a circuit?
From negative to positive.
If the current is 2A and the voltage is 5V, what is the electrical power?
P=2×5=10W
What is the equation for resistance?
R = V / I
What is mean by electromotive force (e.m.f.)?
Electromotive force (e.m.f.) is the electrical work done by a source in moving a unit charge around a complete circuit.
What causes an electric current in a circuit?
The flow of electric charge.
What is an ammeter used for?
To measure electric current.
What is the difference between analogue and digital voltmeters?
Analogue voltmeters show measurements using a needle on a scale, while digital voltmeters display the measurement numerically.
If the work done is 20 Joules and the charge is 5 Coulombs, what is the e.m.f.?
4V
How does the resistance of a metallic wire change when its length is increased?
The resistance increases as the length of the wire increases.
How does the resistance of a metallic wire change when its cross-sectional area is increased?
The resistance decreases as the cross-sectional area increases.
If the current is 3A, the voltage is 4V, and the time is 2 hours, what is the electrical energy used?
Convert time to seconds: 2 hours = 7200 seconds 2hours=7200seconds 𝐸 = 3 × 4 × 7200 = 86400J
If the voltage is 12V and the current is 3A, what is the resistance?
4Ω
If 20 C of charge passes in 10 s, what is the current?
2A
What is the equation for electric current?
I= Q/t , where I:current, Q: charge and t:time
If resistance increases while voltage stays the same, what happens to current?
The current decreases.
What is the equation used to calculate electromotive force (e.m.f.)?
The equation for e.m.f. is E= Q / W , where E is the e.m.f., W is the work done, and Q is the charge.
What particles move to conduct electricity in metals?
electron
what is the unit of e.m.f. measured?
e.m.f. is measured in volts (V).
Write the equation for Ohm’s Law.
V=I×R
What is the equation for electrical power?
P=I×V
What does potential difference (p.d.) mean?
Potential difference (p.d.) is the work done by a unit charge passing through a component.