Current Electricity · Question 37

A wire of resistance R is bent into an equilateral triangle and an identical wire is bent into a square. The ratio of resistance between the two end points of an edge of the triangle to that of the square is

1. 8/9
2. 9/8
3. 32/27
4. 27/32

Answer

(3) 32/27

Solution

Triangle: each side = R3; one side in parallel with the other two sides ( 2R3 )

R1 = R3 2R3R = 2R9

Square: each side = R4; one side in parallel with the other three sides ( 3R4 )

R2 = R4 3R4R = 3R16

R1R2 = 29 163 = 3227

Answer: (3)