Question

A 12 cm wire is given a shape of a right angled
triangle ABC having sides 3 cm, 4 cm and 5 cm
as shown in the figure. The resistance between two
ends (AB, BC, CA) of the respective sides are
measured one by one by a multi-meter. The
resistances will be in the ratio
3 cm
5 cm
BL
4 cm
(1) 3:4:5
(2) 9:16:25
(3) 27:32:35
(4) 21 : 24 : 25

Answer 1

Answer: 3 : 4 : 5

Explanation: as we know that

R = {( p * l)/a }

Now , p & a are same so R is directly proportional to length of wire so the ratio of resistance is same as the ratio of length of the different wires.

Note :- p symbolises resistivity of the substance