A coil is wound as a transformer of rectangular cross section. If all the linear dimension of the transformer are increased by a factor `2` and the number of turns per unit length of the coil remain the same, the self-inductance increased by a factor of

Options

A. 4
B. 8
C. 12
D. 16

Answer

B

Explanation

Self inductance `=mu_(0)n^(2)AL=mu_(0)n^(2)(l xx b)xx L`
n = Total number of turns/length
L = Length of inductor
l = Length of rectangular cross section
b = breadth of rectangular cross - section
So, when all linear dimensions are increased by a factor of 2. The new self inductance becomes L. = 8L.