What is the main purpose of PWM?To control the speed of a motorTo generate a square wave signalTo transmit data over a digital communication channel

The main purpose of Pulse Width Modulation (PWM) is to control the power delivered to an electronic device like a motor, LED, etc. It achieves this by rapidly switching the power supply on and off to simulate a varying level of power. Here are the purposes of PWM mentioned in your question:

1. To control the speed of a motor: PWM is used in DC motor speed control systems. By changing the duty cycle of the PWM signal, we can change the speed of the motor. A higher duty cycle means the motor will run faster, while a lower duty cycle means the motor will run slower.

2. To generate a square wave signal: PWM signals are essentially square wave signals with varying duty cycles. So, yes, one of the uses of PWM is to generate a square wave signal.

3. To transmit data over a digital communication channel: PWM can also be used in digital communication to transmit data. The data is encoded as the width of the pulse, hence the name Pulse Width Modulation.