A 300V DC shunt motor is drawing a full load current of 45A. The armature resistance and shunt field resistance are 0.6Ω and 160Ω respectively. If the torque remains same throughout, by how much should the flux be reduced to increase the speed by 40%?a)22.6%b)28.4%c)31.9%d)35.2%Correct answer is option 'C'. Can you explain this answer?

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A 300V DC shunt motor is drawing a full load current of 45A. The armature resistance and shunt field resistance are 0.6Ω and 160Ω respectively. If the torque remains same throughout, by how much should the flux be reduced to increase the speed by 40%?

a)
22.6%
b)
28.4%
c)
31.9%
d)
35.2%

Correct answer is option 'C'. Can you explain this answer?

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A 300V DC shunt motor is drawing a full load current of 45A. The arma...

T ∝ ∅I_a

since torque is constant and flux and speed are changing. SOt

∅₁I_a1=∅ ₂I_a2

I_a2 = ∅₁ / ∅₂I_a1

Let

∅₁ / ∅₂ = x, then

I_a2 = 45x as I_a1 = 45A

E_b1 = 300 − (0.6 × 45) = 273V

E_b2 = 300 − (0.6 × 45x) = (300 − 27x)V

It is given that N₂= 1.4N₁ since speed is increased by 40% Now, we know E_b∝ N∅

⇒ E_b1 / E_b2 = N1∅₁ / N₂∅₂

382.2 = 300x − 27x²=0

27x² − 300x + 382.2=0

x = 9.64,1.4685

For x = 9.64, the increase in speed criteria is not satisfied. Percentage change in flux

= ∅₁−∅₂ / ∅1

= 1 − ∅₂ / ∅₁= 1 − 11.4685 = 31.9%

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A 300V DC shunt motor is drawing a full load current of 45A. The armature resistance and shunt field resistance are 0.6Ω and 160Ω respectively. If the torque remains same throughout, by how much should the flux be reduced to increase the speed by 40%?a)22.6%b)28.4%c)31.9%d)35.2%Correct answer is option 'C'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about A 300V DC shunt motor is drawing a full load current of 45A. The armature resistance and shunt field resistance are 0.6Ω and 160Ω respectively. If the torque remains same throughout, by how much should the flux be reduced to increase the speed by 40%?a)22.6%b)28.4%c)31.9%d)35.2%Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A 300V DC shunt motor is drawing a full load current of 45A. The armature resistance and shunt field resistance are 0.6Ω and 160Ω respectively. If the torque remains same throughout, by how much should the flux be reduced to increase the speed by 40%?a)22.6%b)28.4%c)31.9%d)35.2%Correct answer is option 'C'. Can you explain this answer?.

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