- #1

Rayanna

- 9

- 1

Two coils are made of copper wires of same length .In the first coil number of turns is 3n and radius is r . In the second coil number of turns is n and radius is 3r the ratio of self inductances of the coil is:

I know that self inductance of a solenoid is μN

where A = area of cross section of frame of solenoid ;so by puting values I get 1:1 which is incorrect ? Please explain me where I am wrong as the correct answer is 3:1.

I know that self inductance of a solenoid is μN

^{2}A/l ;where A = area of cross section of frame of solenoid ;so by puting values I get 1:1 which is incorrect ? Please explain me where I am wrong as the correct answer is 3:1.

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