The main supply voltage to a room is 120 V. The resistance of the lead wires is 6
. A 60 W bulb is already giving light. What is the decrease in voltage across the bulb when a 240 W heater is switched on?
a)
No change
b)
10 V
c)
20 V
d)
More than 10 V
The main supply voltage to a room is 120 V. The resistance of the lead wires is 6 . A 60 W bulb is already giving light. What is the decrease in voltage across the bulb when a 240 W heater is switched on?
a)
No change
b)
10 V
c)
20 V
d)
More than 10 V
Question ID - 150357 | SaraNextGen Top Answer
The main supply voltage to a room is 120 V. The resistance of the lead wires is 6 . A 60 W bulb is already giving light. What is the decrease in voltage across the bulb when a 240 W heater is switched on?
a)
No change
b)
10 V
c)
20 V
d)
More than 10 V
|
The main supply voltage to a room is 120 V. The resistance of the lead wires is 6 |
|||||||
|
a) |
No change |
b) |
10 V |
c) |
20 V |
d) |
More than 10 V |
1 Answer
127 votes
Answer Key / Explanation : (d) -
(d)
.png)
Current 
Voltage across bulb
.png)
Resistance of parallel combination
Total resistance 
Current 
Voltage across parallel combination
Change in voltage 
V.
127 votes
Answer Link
127