Question

a wire of resistance R is bend to form a circle. what is the resistance across the diameter of the circle...

Answer 1

Howdy!!

your answer is ----

Given, resistance of wire is R

when, it is bend in a form of circle then
the resistance across its diameter is ---

1/R' = 1/R/2 + 1/R/2

=> 1/R' = 2/R + 2/R

=> 1/R' = 4/R

=> R' = R/4


hence, the resistance across the diameter of circle is R/4.


hope it help you

Answer 2

Thank you for asking this question, the options for this question are missing:  

Here are the missing options:

A) Rα4π2(2π−α)

B) R2π(2π−α)

C) R(2p  a)

D)  4πRα(2π−α)

Answer:

The correct answer for this question is Option A: Rα4π2(2π−α)

RXWY=R/2πr×(rα)=Rα/2π    

(∵α=l/r)  

and  

RXZY=R/2πr×r(2π−α)

=R/2π(2π−α) Req

=RXWYRXZY/RXWY+RXZY

=Rα/2π×R/2π(2π−α)/Rα/2π+R(2π−α)/2π

=Rα/4π2(2π−α)

If there is any confusion please leave a comment below.