A wire of resistance 
is used to wind a coil of radius 7 cm. The wire has a diameter of 1.4 mm and the specific resistance of its material is 
m. The number of turns in the coil is
Text Solution
Verified by ExpertsThe correct answer is:
D
Let n be the number of turns in the coil. Then total length of wire used, l
Total resistance, 
or, 
n = 70
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