A 6 pole- 230 V- 50 Hz single phase induction motor is rotating in clockwise direction at the 955 rpm- If the rotor resistance at stand still is 6- then value of effective rotor resistance in backward branch of the equivalent circuit will be- Answer upto 2 decimal places

Given rotor resistance at standstill, R = 6 Ω Synchronous speed, N_s =120 fP =120 × 506 = 1000 rpm Slip of rotor, S=N_s N_rN_s=1000 9551000 = 0.045 Slip of ...

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Standard XII

Physics

Magnetic Field

A 6 pole, 230...

Question

A 6 pole, 230 V, 50 Hz single phase induction motor is rotating in clockwise direction at the 955 rpm. If the rotor resistance at stand still is 6 $Ω$ , then value of effective rotor resistance in backward branch of the equivalent circuit will be_________ $Ω$ (Answer upto 2 decimal places)

1.53

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Solution

The correct option is A 1.53
Given rotor resistance at standstill,
$R = 6 Ω$

$Synchronous speed,$
$N_{s} = \frac{120 f}{P} = \frac{120 \times 50}{6} = 1000 r p m$

$Slip of rotor,$
$S = \frac{N_{s} - N_{r}}{N_{s}} = \frac{1000 - 955}{1000} = 0.045$

$Slip of rotor w.r.t backward field,$
$2 - s = 2 - 0.045 = 1.955$

$effective rotor resistance = \frac{R_{2}}{2 (2 - s)} = \frac{6}{2 \times 1.955} = 1.53 Ω$

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A 6 pole, 230 V, 50 Hz single phase induction motor is rotating in clockwise direction at the 955 rpm. If the rotor resistance at stand still is 6Ω, then value of effective rotor resistance in backward branch of the equivalent circuit will be_________Ω (Answer upto 2 decimal places) 1.53

The correct option is A 1.53Given rotor resistance at standstill, R=6 Ω Synchronous speed, Ns=120fP=120×506=1000 rpm Slip of rotor, S=Ns−NrNs=1000−9551000=0.045 Slip of rotor w.r.t backward field, 2−s=2−0.045=1.955 effective rotor resistance =R22(2−s)=62×1.955=1.53 Ω

A 6 pole, 230 V, 50 Hz single phase induction motor is rotating in clockwise direction at the 955 rpm. If the rotor resistance at stand still is 6 $Ω$ , then value of effective rotor resistance in backward branch of the equivalent circuit will be_________ $Ω$ (Answer upto 2 decimal places)

1.53