Choose the correct expression for the armature current of a DC motor.
1
\(I_a=\frac{E_b}{R_a}\)
2
\(I_{\mathrm{a}}=\frac{V+E_{\mathrm{b}}}{R_{\mathrm{a}}}\)
3
\(I_a=\frac{V E_b}{R_s}\)
4
\(I_{\mathrm{a}}=\frac{V-E_{\mathrm{b}}}{R_{\mathrm{a}}}\)
5
Question Not Attempted