Question

Pls give the answer with explanation I will mark you brainliest....

Answer 1

$\huge\bigstar\underline\pink{ANSWER}$

[ CHECK ATTACHMENT ]

when, switch is connected...points A and B are on zero potential...

so, to make the circuit easy... connect them.

now, (for parallel combination)

1/Req= 1/R +1/3R = 4/3R

Req= 3R/4 (for XAB)

similarly..for (YAB). ..

Req= 3R/4

now, they are in series...

Req = 3/4R +3/4R. = 6/4R. = 3/2R

so, your answer is option( C)

Happy to help☺️

Answer 2

If switch is open the current will flow through all resistances.

but if switch is closed it will be a short circuit and all the current will flow through R and 3R. so equivalent resistance=3R+R=4R. option (4) is correct.

HOPE THIS HELPS YOU