Change in total power with modulation index

What is the change in the value of transmitted power when the modulation index changes from 0 to 1?

a.) 100%
b.) Remains unchanged
c.) 50%
d.) 80%

Correct Answer: c) 50%

Explanation:

P_t= P_c ( 1 + m²/2)

P_t= P_c ( 1 + 0²/2) = P_c……………..(1)

New total power P_t1= P_c ( 1 + 1²/2)
= P_c *3/2……………..(2)
(2) / (1),

We get , P_t1/ P_t= 3/2= 1.5
P_t1= 1.5 P_t
i.e. there is increase in total power by 50%