Electricity - OCR AS-level

Front

What is the definition of potential difference (p.d.)?

Back

The potential difference (p.d.) across a component is the work done per unit charge in moving a charge through the component.

Front

What is the formula for calculating power (P) in an electrical circuit?

Back

P = V × I, where P is power in watts, V is potential difference in volts, and I is current in amperes.

Front

What is the relationship between charge (Q), current (I), and time (t)?

Back

Q = I × t, where Q is charge in coulombs, I is current in amperes, and t is time in seconds.

Front

What is the definition of resistance (R)?

Back

Resistance (R) is a measure of the opposition to the flow of electric current, measured in ohms (Ω).

Front

What is Ohm's Law?

Back

Ohm's Law states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points, expressed as V = I × R.

Front

What is the formula for total resistance (R_total) in a series circuit?

Back

R_total = R1 + R2 + ... + Rn, where R1, R2, ..., Rn are the resistances of individual components.

Front

What is the formula for total resistance (R_total) in a parallel circuit?

Back

1/R_total = 1/R1 + 1/R2 + ... + 1/Rn, where R1, R2, ..., Rn are the resistances of individual components.

Front

What is the definition of electromotive force (e.m.f.)?

Back

Electromotive force (e.m.f.) is the energy provided by a cell or battery per coulomb of charge, measured in volts (V).

Front

How do you calculate the charge (Q) passing through a circuit?

Back

Q = I × t, where I is the current in amperes and t is the time in seconds.

Front

What is the significance of internal resistance in a battery?

Back

Internal resistance affects the efficiency of a battery, causing a voltage drop when current flows, reducing the output voltage available to the circuit.