6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Two identical lamps are connected to the same 6 V battery, first in series with each other and then in parallel with each other.
Compare the two circuits. In your answer you should describe how the potential difference across each lamp, the current through each lamp, and the brightness of the lamps differ between the series and parallel arrangements, and explain these differences. (6 marks)
A resistor has a current of 0.40 A flowing through it when it is connected to a 12 V supply.
(a) Calculate the resistance of the resistor. Use V=IR. Show your working and give the unit. (2 marks)
(b) Calculate the charge that flows through the resistor in 2 minutes. Use Q=It (convert the time to seconds). Show your working and give the unit. (2 marks)
An electric motor draws a current of 3.0 A when connected to a 230 V mains supply.
(a) Calculate the power transferred by the motor. Use P=VI. Show your working and give the unit. (2 marks)
(b) The same current of 3.0 A flows through a heating element of resistance 20 Ω. Calculate the power dissipated in the element. Use P=I2R. (1 mark)
A straight wire carrying a current of 4.0 A is placed at right angles to a magnetic field of flux density 0.30 T. The length of wire in the field is 0.25 m. This is an example of the motor effect.
(a) Calculate the force on the wire. Use F=BIL. Show your working and give the unit. (2 marks)
(b) State one change that would make the force on the wire larger. (1 mark)
A plastic rod is rubbed with a dry cloth. After rubbing, the rod becomes negatively charged.
Explain, in terms of the movement of electrons, how the plastic rod becomes negatively charged. (2 marks)
A bar magnet has a magnetic field around it.
State the direction in which the magnetic field lines point around a bar magnet (with reference to its poles). (1 mark)