Question

answer this.....please

Answer 1

answer will be 3/15.
as 1/AB=1/(1+3)+1/1.5

Answer 2

According to the attachment,

1 Ω and 2 Ω are in a series connection to each other.

Hence they can be collectively written as 3 Ω.

Also according to the diagram, 3 Ω and 1.5 Ω are in parallel connection.

Hence we can say that,

1 / R = 1 / 3 + 1 / 1.5

Taking LCM we get,

1 / R = 1.5 + 3 / 3 * 1.5

1 / R = 4.5 / 4.5

=> 1 / R = 1 / 1

=> R = 1

Hence the resistance is 1 Ω.

Hence the Effective Resistance across A and B is 1 Ω.

Hope it helped !