PhysicsUK Connections

• 4.2.1(a) Recognise and use standard circuit symbols.
• 4.2.1(b) Construct and interpret circuit diagrams using correct symbols.
• 4.2.2(a) Define potential difference (p.d.) and state the unit volt.
• 4.2.2(b) Define electromotive force (e.m.f.) of a source such as a cell or power supply.
• 4.2.2(c) Distinguish between e.m.f. and p.d. in terms of energy transfer.
• 4.2.2(d) Use energy transfer equations W = VQ and W = EQ.
• 4.2.2(e) Use energy transfer for charged particles: eV = ½mv² for electrons and other charged particles.
• 4.2.3(a) Define resistance using R = V / I and state the unit ohm.
• 4.2.3(b) State and apply Ohm’s law.
• 4.2.3(c)(i) Describe and sketch I–V characteristics for resistor, filament lamp, thermistor, diode and LED.
• 4.2.3(c)(ii) Use techniques and procedures to investigate electrical characteristics of ohmic and non-ohmic components.
• 4.2.3(d) Describe how the resistance of a light-dependent resistor (LDR) varies with light intensity.
• 4.2.4(a)(i) Define resistivity using R = ρL / A.
• 4.2.4(a)(ii) Use techniques and procedures to determine the resistivity of a metal.
• 4.2.4(b) Describe variation of resistivity of metals and semiconductors with temperature.
• 4.2.4(c) Understand the negative temperature coefficient (NTC) thermistor and variation of resistance with temperature.
• 4.2.5(a) Use and apply power equations P = IV, P = I²R, and P = V² / R.
• 4.2.5(b) Use energy transfer equation W = VIt.
• 4.2.5(c) Recognise the kilowatt-hour (kWh) as a unit of energy and calculate cost of electrical energy.

H156 v2.0 · May 2026