An AM transmitter is coupled to an aerial. The input current

An AM transmitter is coupled to an aerial. The input current is observed to be 5 A. With modulation the current value increases to 5.9 A. The depth of modulation is—

Given that I_t = 5·9 A (modulated current)
I_c = 5 A (unmodulated current)
We know that

I_t = I_c	√	1 +	μ²
			2

5.9 = 5	√	1 +	μ²
			2

μ²	=		5.9		²	− 1
2			5

or μ² = 0.7848
or μ = 0.8858
or μ = 88.6%