Current, Potential Difference & ResistanceEdexcel GCSE Physics: Flashcards

Card 1 of 140 of 14 known

Question

Define electric current.

Tap or press Space to reveal

Tap card or press Space to flip

See all 14 cards

Define electric current.: The rate of flow of electric charge, measured in amperes (A).
What carries current in a metal?: A flow of electrons.
Give the equation linking charge, current and time.: Q = I × t (charge = current × time).
Define potential difference.: The energy transferred per unit charge passed between two points in a circuit, measured in volts.
What is one volt equal to?: One joule per coulomb.
Give the equation linking energy transferred, charge and potential difference.: E = Q × V (energy transferred = charge × potential difference).
How is a voltmeter connected in a circuit?: In parallel with the component being measured.
How is an ammeter connected in a circuit?: In series with the component being measured.
Give the equation linking potential difference, current and resistance.: V = I × R (potential difference = current × resistance).
What happens to total resistance when resistors are added in series?: Total resistance increases.
What happens to total resistance when resistors are added in parallel?: Total resistance decreases.
State the rule for current at a junction.: Current is conserved — total current flowing in equals total current flowing out.
What does a variable resistor do?: Changes the resistance in a circuit, allowing the current to be controlled.
A charge of 15 C passes a point in 5 s. What is the current?: 3 A (I = Q ÷ t = 15 ÷ 5 = 3 A).