Question

A battery E is connected to three indentical
lamps P,Q and R as shown
in figure. Initially, the switch
S is kept open and the lamb
P and Q are observed to glow
with same brightness. Then switch
S is closed. How will the brightness
of glow of bulbs P and Q will
Change. Justify your answer​

Answer 1

Answer:

this is because bulb p and q are attached to positive terminal of battery.so when the switch was open then the electricity was not passing through bulb R but when switch was closed then electricity was passing through bulb R.