Question

Two resistors of resistances 1 ohm and 2 ohm are connected in series in the circuit to a 3
V battery. What would be the reading of ammeter and the voltmeter connected to 2 ohm
resistor when the circuit is closed?​

Answer 1

the two resistances are connected in series combination. So the net resistance of the circuit becomes R=1Ω+2Ω

⇒R=3Ω

The battery is of 3V.

So the current flowing in the circuit is given by the Ohm’s law as V = IR

3=3I

3=3I ⇒I=1A …………………...(1)

The ammeter is connected in series with the circuit. So its reading will show the value of the current flowing in the circuit. Hence, the reading of the ammeter is equal to 1A.

Now, the voltmeter is connected in parallel combination with the 2Ω resistance. So its reading will represent the potential difference across the 2Ω resistance. The potential difference across the 2Ω resistance is given by the Ohm’s law as V=IR

Substituting (1) and R=2Ω above, we get V=1×2V ⇒V=2V

Hence, the voltmeter will show a reading of 2V.