Current Electricity Charging Discharging Of Capacitors Question 438

Question: Forty electric bulbs are connected in series across a 220 V supply. After one bulb is fused, the remaining 39 are connected again in series across the same supply. The illumination will be

[NCERT 1972; Haryana CEE 1996; DPMT 2001]

Options:

A) More with 40 bulbs than with 39

B) More with 39 bulbs than with 40

C) Equal in both the cases

D) In the ratio of $ 49^{2}:39^{2} $

Show Answer

Answer:

Correct Answer: B

Solution:

When 1 bulb fuses, the total resistance of the circuit decreases hence the current increases. Since $ P=i^{2}R $ ,

Therefore illumination increases.