**Contents**show

## What affects the speed of the motor?

The rotating speed of an electric motor depends on two factors: its physical construction, **and the frequency (Hz) of the voltage supply**.

## What is major factors that affect motor speed and torque?

Input Voltage: For a fixed load, the speed of the motor is affected by the applied voltage. **Increase in voltage = increase in speed**. Load Torque: For a fixed voltage, the speed of the motor is inversely affected by the load. Increase in load torque = decrease in speed.

## What are the different factors affecting the speed of dc motor?

The factors affecting DC control are therefore:

**The applied voltage**. **The flux**. **The voltage across an armature**.

## What increases the speed of a motor?

Increasing the speed can be achieved by **increasing the supply frequency** as the speed and frequency are directly proportional; however, there are two constraints. The first is the saturation of the magnetic circuit, but this issue can be significantly avoided by keeping the V/f ratio constant.

## What is the speed of a DC motor?

DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and **1000-5000 rpm for DC fractional hp motors**.

## Can you vary the speed of an AC motor?

Although they are constant speed devices, AC motor **speeds can vary if the frequency, input voltage**, or the windings that make the motor rotate are changed. A common and efficient means of changing a motor’s speed is to vary the frequency by use of an inverter as the power source.

## Does current affect motor speed?

The current through the motor times the resistance of the motor creates a small voltage that must be subtracted from the applied voltage. As the load and current **increase**, this IR drop also increases causing the motor to lose a little speed.

## What are the factors affecting torque?

Examples: Page 5 Torque is Determined by Three Factors: **The magnitude of the applied force.** The direction of the applied force. The location of the applied force.

## Which is a better method to control motor speed?

Thus, the speed of a DC motor can be controlled in three ways: By **varying the supply voltage**. **By varying the flux**, and by varying the current through the field winding. By varying the armature voltage, and by varying the armature resistance.

## What factors will affect the rotation of the simple electric motor?

**The speed of rotation of the coil can be increased by:**

- increasing the size of the current;
- using a stronger magnet;
- increasing the number of turns of wire in the coil;
- reducing friction between the coil and the axel it rotates on.

## What are the common methods used to vary the speed of a separately excited DC motor?

2 Speed control techniques in separately excited dc motor: i) **Varying the armature voltage in the constant torque region**. ii) In the constant power region, field flux should be reduced to achieve speed above the rated speed.

## Which motor is more efficient?

AC motors are generally considered to be more powerful than **DC motors** because they can generate higher torque by using a more powerful current. However, DC motors are typically more efficient and make better use of their input energy.