Question

For higher diverter resistance, speed-torque characteristic will lie ____________

(a) Above speed-torque characteristic of lower resistance

(b) Below speed-torque characteristic of lower resistance

(c) On the speed-torque characteristic of lower resistance

(d) Cannot say

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Asked question is from Speed Control Using Field Control of Series Motor in section DC Motors of DC Machines

Answer 1

Correct answer is (b) Below speed-torque characteristic of lower resistance

The explanation is: Speed-torque characteristic for decreasing values of diverter resistance or decreasing value of kd will lie above of the previous or lower value of diverter resistance. Thus, for higher diverter value curve will lie below the previous one.