(a) How is the bulb A connected with the mains? At what voltage does it glow?
(b) How are the bulbs B and C connected with the mains? At what voltage does the bulb B glow?
(c) How is the glow of bulbs A and C affected if bulb B gets fused?
(d) How is the glow of bulbs B and C affected if bulb A gets fused?
Solution:
(a) Bulb A is wired in series with the mains. When the voltage applied across the bulb is 220 V, the bulb A lights.
(b) The mains are connected in series with bulbs B and C. Due to the series connection with the mains, the voltage at which they flash will be divided by two from the mains supply voltage. As a result, bulb B will light up at 110 volts.
(c) If bulb B fails, bulb C, which is connected in series with bulb B, will not light. Because bulb A is connected in parallel with the mains, this will have no effect on its radiance.
(d) If bulb A fails, the light of bulbs B and C will not be altered.