The rotor frequency of a 4 pole, 60 Hz induction motor having full load slip of 5% at rated load is: 3 Hz 6 Hz 600 Hz 1200 Hz Correct answer: 1. 3 Hz From formula: fr = sfe where fr = Rotor’s frequency fe = 60 Hz s = slip fr = 0.05 * … Read more
Usually, a Single Phase Induction Motor has the number of poles: 2 4 8 16 Correct answer: 2. 4
For same ratings which one of Induction motors the following is larger in size: Single-phase Induction motor Three-phase Induction motor Both are same in size Correct answer: 1. Single-phase induction motor Explanation: For same rating a single-phase induction motor is larger in size as compared to three-phase induction motor
A 4 pole, 50 Hz Induction Motor Has a Slip of 5%. The Speed of motor is: 1425 RPM 1500 RPM 1578 RPM 1788 RPM Correct answer: 1. 1425 RPM The basic formula for formula for Synchronous Speed of Induction Machine is: ηsync= 120*f /P ηsync= 120*f /P = 120 * 60/4 = 1500 RPM … Read more
A 4 pole, 60 Hz Induction Motor Has a Slip of 5%. The Speed of motor is: 1710 RPM 1800 RPM 1894 RPM 2245 RPM Correct answer: 1. 1710 RPM The basic formula for formula for Synchronous Speed of Induction Machine is: ηsync= 120*f /P ηsync= 120*f /P = 120 * 60/4 = 1800 RPM … Read more
The synchronous speed of 4 pole, 50 Hz Induction Motor is: 750 RPM 1500 RPM 3000 RPM 6000 RPM Correct answer: 2. 1500 RPM Explanation: From formula of synchronous speed of induction motor: ηsync= 120*f /P = 120 * 50/4 = 1500 RPM
The synchronous speed of 60 Hz, 4 Pole Induction Motor is: 900 RPM 1800 RPM 3600 RPM 7200 RPM Correct answer: 2. 1800 RPM Explanation: From Formula of synchoronous speed of induction motors magnetic fields: ηsync= 120*f /P Here f = 60 Hz P = 4 pole So Speed = 120 * 60 / 4 … Read more
The correct formula for Synchronous Speed of Induction Machine: ηsync= 240*f /P ηsync= 120*f /P ηsync= 120/(f*P) ηsync= 120*f /3P Correct answer: 2. ηsync= 120*f /P The sychronous speed or speed of rotation of magnetic fields can be mathematically expressed by the following relationship: ηsync= 120*f /P where f = frequency P = Number of … Read more
The Correct Relationship between Slip, Synchronous, and Rotor speed of Induction Motor is: ηslip = ηsyn + ηm ηslip = ηsyn – ηm ηslip = 1/(ηsyn + ηm) ηslip = 1/(ηsyn – ηm) Correct answer: 2. ηslip = ηsyn – ηm Rotor slip speed or simply slip speed of Induction Motor is defined as the … Read more
The Induction Motor Runs at the speed which is: Same as Synchronous speed Lower than synchronous speed Higher than synchronous speed Any of above Correct answer: 2. Lower than synchronous speed