A battery with an internal resistance of 1 Ω and an unknown emf (ε) is connected in a circuit, as shown below. A high-resistance voltmeter (V) is connected across the battery. A1 and A2 represent ammeters of negligible resistance.
With switch S closed, the current passing through the 8 Ω resistor is 0,5 A.
9.1 State Ohm’s law in words. (2)
9.2 Calculate the reading on ammeter A1. (4)
9.3 If device R delivers power of 12 W, calculate the reading on ammeter A2. (5)
9.4 Calculate the reading on the voltmeter when switch S is open. (3)
[14]