Torque equation of SM

What is the torque equation of a synchronous motor?

• A) T = P/ω

• B) T = P/2πf

• C) T = kφI

• D) T = V^2/R

What is the relationship between torque and armature current in a synchronous motor?

• A) T is proportional to Ia

• B) T is inversely proportional to Ia

• C) T is independent of Ia

• D) T is proportional to Ia^2

In a synchronous motor, what is the effect of increasing the excitation current?

• A) Increases the torque

• B) Decreases the torque

• C) Has no effect on the torque

• D) Causes the motor to stall

n a synchronous motor, what is the relationship between the stator voltage and the torque?

• A) T is proportional to V

• B) T is inversely proportional to V

• C) T is independent of V

• D) T is proportional to V^2

The torque produced by a synchronous motor is proportional to which of the following?

• A. Magnetic field strength

• B. Armature current

• C. Power factor

• D. All of the above

The torque of a synchronous motor can be controlled by:

• A. Changing the excitation current

• B. Changing the load

• C. Changing the power factor

• D. All of the above

In a synchronous motor, the rotor rotates at:

• A. The same speed as the stator magnetic field

• B. A speed slightly slower than the stator magnetic field

• C. A speed slightly faster than the stator magnetic field

• D. A random speed

The starting torque of a synchronous motor is:

• A. Zero

• B. Low

• C. High

• D. Same as the full load torque

In a synchronous motor, the armature winding is:

• A. Short-circuited

• B. Open-circuited

• C. Connected to a load

• D. Connected to a capacitor

What is the power factor of a synchronous motor operating at no load?

• A. Unity

• B. Leading

• C. Lagging

• D. Zero