In 'normal driving conditions', an electric car has a range of 150 km. This uses all of the 200 MJ of energy stored in its batteries. With the batteries initially fully charged, the car is driven 100 km in 'normal driving conditions'. The batteries are then recharged from a household electrical supply delivering a constant current of 13.0 A at a potential difference of 230 V. What is the minimum time required to recharge the batteries?

A power cable X has resistance R and carries current I. A second cable Y has resistance 2R and carries current I/2. W…

A low-voltage supply with an e.m.f. of 20 V and an internal resistance of 1.5 Ω is used to supply power to a heater o…

A cell of e.m.f. E delivers a charge Q to an external circuit. Which statement is correct?

A 12 V battery is charged for 20 minutes by connecting it to a source of electromotive force (e.m.f.). The battery is…

A sample of an isotope emits β⁻ particles. The emitted β⁻ particles have a range of energies. What must also be emitted?

A nucleus of magnesium decays into a nucleus of sodium by emitting a β⁺ particle. The decay is represented by the equ…