Power Electronics - Engineering

Q1:

A fully controlled bridge converter is feeding an RLE load. The load current is I0. The input voltage is Vm sin ωt. The KVL equation to find firing angle a is

A
cos a = E + I0R

B
cos a = E + I0R

C
cos a = E - I0R

D
cos a = E - I0R

ANS:A -

cos a = E + I0R

Why not option C?