Current, potential difference and resistanceEdexcel A-Level Physics: Mind map

Exam questions on Current, potential difference and resistance

1. A phone charger delivers a constant current of 2.0 A at a potential difference of 5.0 V. A phone is charged for 45 minutes.
   Calculate the number of electrons that pass through the charger cable each second. The charge of an electron is 1.60 × 10⁻¹⁹ C.2 marks
2. A student investigates a filament lamp. When the potential difference across the lamp is 6.0 V the current is 1.5 A, and when it is 12 V the current is 2.0 A.
   Use the data to explain why the filament lamp does not obey Ohm's law.2 marks
3. The heating element of an electric kettle is connected to a 230 V supply. When the water is boiling the element carries a steady current of 8.7 A for 3.0 minutes.
   Calculate the charge that passes through the element and the energy it transfers in this time.3 marks