Question

a circle is constructed of a uniform wire of resistance of 2 ohm per cm and is connected in a circuit such that it offers maximum resistance. fins the maximum resistance.(take radius of the circle as 7 cm) ​

Answer 1

The radius of the wire is given as 7 cm. The length of the wire is the circumference of the circle.
So,
Length = 2π r = 2 x 227×7= 44 cmNow, Resistance per unit length = 2 ohmSo, total resistance = resistance per unit length × length = 44 ×2=88 ohm

The resistance will be maximum if it is connected in series.

Thus, the maximum resistance is 88 ohm.

Hope it helps.