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Explanation: In case of DC motor, the speed is proportional to the back emf (Ea ∝ N). So, with the increase in speed, the back emf also increases. Therefore, armature current is also decreased, in case of series motor, armature current is equal to the line or load current.

## What happens when speed of DC motor is increased?

A DC motor is a device which converts electrical energy such as voltage and current into mechanical energy like speed. … Thus, when the speed of the dc motor is increased, the armature current will decrease.

## What affects the speed of a DC motor?

DC Motor Speeds

The number of wire turns in an armature, the operating voltage of the motor, and the strength of the magnets all affect motor speed. If a DC motor is running on a 12 V battery, that is the maximum voltage available to the unit and the motor will only be able to perform at a speed rated for 12 V.

## When speed of DC motor increases what will be the effect on torque?

Without a mechanical load torque is meaningless except for the mechanical losses in the motor. in theory Ke == Kt, but Kt is effected by iron characteristics (hence why two exist). The Reason that Torque and Speed are said to be inversely proportional is the ability to generate torque diminishes with increase speed.

## 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.

## When speed of DC motor increases the back EMF?

If the speed of the motor is high, then back e.m.f. Eb (= PφZN/60 A) is large and hence the motor will draw less armature current and vice-versa.

## How can the speed of a DC series motor be increased?

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.

## How do DC motors control speed?

Thus, the speed of a DC motor can control in three ways:

- By varying the flux, and by varying the current through field winding.
- By varying the armature voltage, and the armature resistance.
- Through the supply voltage.

## What are the factors on which the speed of a motor depends?

The electric motor speed depends on both the applied voltage and the number of turns of its coil. The more turns the motor has the higher the strength of the rotor magnetic field if the current is maintained constant.

## Does voltage affect motor speed?

Back to the original question: how does voltage affect speed? From the analysis above, we can see that when the load (torque) on the motor is constant, speed is directly proportional to supply voltage. And, when the voltage remains constant, an increase in the load (torque) on the motor results in a decrease in speed.

## Why does current increase when DC motor is increased?

Why does armature current increase when load on the DC motor increase? When the load increases the motor slows down. This reduces the counter EMF. This allows a higher current to flow.

## What is the effect of increase in speed of a DC motor on the back EMF and the line current?

Explanation: In case of DC motor, the speed is proportional to the back emf (Ea ∝ N). So, with the increase in speed, the back emf also increases. Therefore, armature current is also decreased, in case of series motor, armature current is equal to the line or load current.

## Why speed decreases as load increases?

In case of DC shunt motor, the flux per pole is considered to be constant, torque increases with the increase of load current. If the load current increases then the armature current also be increased and the speed slightly falls due to increase in voltage drop in armature.

## How do you increase the speed of a motor in physics?

The speed of the motor can be increased by:

- increasing the strength of the magnetic field.
- increasing the current flowing through the coil.