question_answer

Four identical bulbs A, B, C, D are connected in a circuit as shown in figure. Now whenever any bulb fails, then it cannot conduct current through it. Then Ideal Battery?

[a] Brightness of bulb C is highest

[b] If C fails, brightness of bulb D increases

[c] If C fails, brightness of all bulbs remain same

[d] If A fails, B will not glow

Correct option is-

A) a, c, d              

B) a, b, d

C) c, d                  

D)   b, d

Correct Answer: A

Solution :

Potential difference across D is zero so it will not glow at all. Potential across C is maximum. \[\therefore \] It will glow maximum and if C fuses then also potential across each bulb will remain same. Brightness of each bulb will remain same.