Question

How will be the reading in the ammeter A affected if another identical bulb Q is connected in parallel to P? (The voltage in the mains is maintained at a constant value.)

(A) The reading will be reduced to one-half. 

(B) The reading will not be affected. 

(C) The reading will be doubled. 

(D) The reading will be increased four-fold

Answer 1

Correct option  (C) The reading will be doubled. 

Explanation:

Let, resistance of bulb P and Q be R. So, reading of ammeter before connecting Q to the circuit is 

After connecting Q to the circuit, resultant resistance of the circuit is

Thus, new reading of ammeter will be