Question

Seven identical lamps of resistance 2200 ohms each are connected to 220 volts line as shown in the figure. What will be the reading in the ammeter ?

• A. $\frac{1}{10}amphere$
• B. $\frac{3}{10}ampere$
• C. $\frac{4}{10}ampere$
• D. $\text{None of these}$

Answer 1

The correct option is D $\text{None of these}$

The voltage across the each lamp is 220V and the resistance of each lamp is 2200$\Omega$.
current drawn by each lamp $=\frac{220}{2200}=\frac{1}{10}$amp.
Ammeter records the sum of current of the 5 lamps behind it, which while returning meet at the node to which ammeter is connected. So, reading of the ammeter$=\frac{5}{10}$amp.