Question

A wire of resistance 16Ω is cut into four equal parts, each part is stretched to the original length of the wire, then each streteched part first connected in series than in parallel, the ratio of resistance will be.

(1) 16 : 1

(2) 1 : 16

(3) 4 :1

(4) 1 : 4

Answer 1

(1) 16 : 1

Resistance of each part on cutting = 4Ω 

After stretching resistance of each part will be 16 times = 64Ω 

Effective resistance in series = 64 x 4 = 256Ω 

Effective resistance in parallel 64/4 = 16Ω

∴ Ratio of resistances in series to parallel = 256 : 16 = 16 : 1