Electrical current depends on resistance and potential difference. Different electrical components have different characteristics. These can be investigated using suitable circuits and apparatus.
What is the unit of resistance?
What happens to the resistance of a piece of resistance wire as it gets hotter?
Its resistance increases
Its resistance stays the same
Its resistance decreases
What is the total resistance of two 8 Ω resistors connected in series?
What does the current–voltage graph for a linear circuit component show?
A straight line passing through the origin, showing that current is directly proportional to potential difference
A curved line passing through the origin, showing that current is not directly proportional to potential difference
A straight line passing through the origin, showing that current is inversely proportional to potential difference
Which statement about thermistors is correct?
Their resistance decreases as the light intensity increases
Their resistance increases as the temperature increases
Their resistance decreases as the temperature increases
What current flows in a 100 Ω resistor with a potential difference of 5 V across it?
A 3 kW heater is switched on for 3 hours. How much energy is transferred in this time?
How much energy is transferred by a 250 W television set in 4 minutes?
How much power is transmitted by a current of 2.0 A flowing at a potential difference of 5.0 V?
How much power is transmitted by a current of 2.0 A flowing through a 6.0 Ω resistor?