Question

A dc series motor has an armature resistance of 0.06 ? and series field resistance of 0.08 ?. The motor is connected to a 400 V supply. The line current is 20 A when the speed of the machine is 1100 rpm. When the line current is 50 A and the excitation is increased to 30%. i) write teh relation between magnetic fluxes in both cases. (1mark) ii) Find the speed of the machine in rpm when the line current is 50 A (2 mark)

          A dc series motor has an armature resistance of 0.06 ? and series field resistance of 0.08 ?. The motor is connected to a 400 V supply. The line current is 20 A when the speed of the machine is 1100 rpm. When the line current is 50 A and the excitation is increased to 30%.
i) write teh relation between magnetic fluxes in both cases. (1mark)
ii) Find the speed of the machine in rpm when the line current is 50 A (2 mark)

A dc series motor has an armature resistance of 0.06 ? and series field resistance of 0.08 ?. The motor is connected to a 400 V supply. The line current is 20 A when the speed of the machine is 1100 rpm. When the line current is 50 A and the excitation is increased to 30%.
i) write teh relation between magnetic fluxes in both cases. (1mark)
ii) Find the speed of the machine in rpm when the line current is 50 A (2 mark)

Added by Diane S.

University Physics with Modern Physics

Hugh D. Young 14th Edition

Instant Answer

Solved by Expert Sri K

06/11/2023

Step 1

- The armature resistance (Ra) is 0.06 Ω. - The series field resistance (Rse) is 0.08 Ω. - The total supply voltage (V) is 400 V. - The initial line current (I1) is 20 A, with a corresponding speed (N1) of 1100 rpm. - The final line current (I2) is 50 A, and the Show more…

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A DC series motor has an armature resistance of 0.06 Ω and series field resistance of 0.08 Ω. The motor is connected to a 400 V supply. The line current is 20 A when the speed of the machine is 1100 rpm. When the line current is 50 A and the excitation is increased to 30%. i) write the relation between magnetic fluxes in both cases. ii) Find the speed of the machine in rpm when the line current is 50 A.