Question

When load current of a dc series motor is increased, then

• A. \( \text{speed decreases non-linearly and torque increases non-linearly} \)
• B. \( \text{flux increases non-linearly and torque increases linearly} \)
• C. \( \text{speed decreases linearly and torque increases non-linearly} \)
• D. \( \text{speed decreases non-linearly and torque increases linearly} \)

Hint:

For a DC series motor prior to saturation: - Torque vs Current is parabolic ($T \propto I_a^2$) $\rightarrow$ Non-linear! - Speed vs Current is hyperbolic ($N \propto 1/I_a$) $\rightarrow$ Non-linear! Both curves are distinctly non-linear lines.

Answer 1

The Correct Option is A