The diagrams show the electric fields around two different positive point charges.
An identical positive test charge is placed at the same distance d d\,d from the central charge in both electric fields.
Explain in which electric field, A or B, the test charge experiences the strongest force.
For a continuous electric current to flow in a circuit, which conditions must be met?
Tick (✓\checkmark✓) two boxes:
- complete / closed conducting path
- infinite resistance
- source of potential difference
- open-loop circuit
A student has written two sentences about different electrical components:
"The resistance of a thermistor decreases as the light intensity of the surroundings increases."
"The resistance of an ohmic conductor increases as the current through it increases."
The student has made two mistakes about the components.
Identify the mistakes and write the correct word or words to replace each of them.
Calculate the current in a 1200 W electric heater when the potential difference across it is 240 V.
Use the equation:
power=potential difference×current \text{power} = \text{potential difference} \times \text{current} power=potential difference×currentCalculate the energy transferred when a charge of 75 C moves through a potential difference of 12 V.
Use the equation:
energy transferred=charge flow×potential difference \text{energy transferred} = \text{charge flow} \times \text{potential difference} energy transferred=charge flow×potential difference