Question

In an electrical circuit, three incandescent bulbs A, B and C of rating 40 W, 60 W and 100 W respectively are connected in parallel to an electric source. Which of the following is likely to happen regarding their brightness? 

(a) Brightness of all the bulbs will be the same 

(b) Brightness of bulb A will be the maximum 

(c) Brightness of bulb B will be more than that of A 

(d) Brightness of bulb C will be less than that of B

Answer 1

The answer is (c) Brightness of bulb B will be more than that of A

• Bulbs are connected in parallel so resistance of combination would be less than arithmetic sum of resistance of all the bulbs. 
• So there will be no negative effect on flow of current. 
• As a result, bulbs would glow according to their wattage.