A six-pole three-phase 440-v, 60 Hz induction motor develops 10-hp at 1,150 rpm, the power factor being 80% lagging. Stator and core losses amount to 400 w and 350 w, respectively. Frictional losses amount to 0.5-hp. Calculate the motor line current.
A12.24 A
B13.41 A
C11.42 A
D14.64 A
#42📜 EE Pre-Board March 2018📘 PowerhouseMedium
A three-phase, 6 pole, 50 Hz induction motor develops a maximum torque of 30 N·m at 960 rpm. Calculate the torque produced by the motor at 6% slip. The rotor resistance per phase is 0.6 Ω.
A24.7 N-m
B25.7 N-m
C26.7 N-m
D27.7 N-m
#43📜 EE Pre-Board August 2018📘 PowerhouseMedium
A 440V, 60Hz, 6 pole, 3 phase induction motor has a rotor input power of 33kW at rated voltage and frequency. Under this condition, the rotor emf makes 126 complete cycles/minute. Find the rotor resistance in ohms/phase if the rotor current is 60A/phase.
A0.0118
B0.0107
C0.107
D0.118
#44📜 EE Pre-Board August 2018📘 PowerhouseEasy
An induction motor with 8 poles, 60 Hz is operated with a slip of 3%. Calculate the rotor speed.
A1,684
B1,024
C873
D927
#45📜 EE Pre-Board August 2018📘 PowerhouseEasy
A 60 Hz, 4 pole, 3 phase induction motor has a slip of 2.5 %. What is the slip speed in rpm ?
A55
B40
C60
D45
#46📜 EE Pre-Board August 2018📘 PowerhouseMedium
A 15 hp, 460 V, 60 Hz, 6-pole, 3 phase induction motor has full-load slip of 4%. Find the full-load torque in N-m.
A85
B88
C93
D90
#47📜 EE Pre-Board August 2018📘 PowerhouseEasy
The starting current of a 15 hp, 460 v, 3 phase induction motor is 130 A. What voltage in volts should be applied to the motor so that the starting current will not exceed 84.8 A.
