Test: Interfacing With Motors - Computer Science Engineering (CSE) MCQ

Electromagnetic relays are the devices that are used for switching of devices like motors, that operates on the principle of electromagnetic induction.

In DPDT relays, there are double pole or two contacts are found namely normally open and normally closed contacts, so it is called a double pole, double throw relays.

We need a ULN2803 for driving a relay because more current is generally required for driving a relay that is generally not provided by a micro controller, so we need a ULN2803 to increase the current limit.

Solid relays are advantageous over electromagnetic relays because they are faster as they consume less current to be energised.

 Optoisolators are devices that can be used as an electromagnetic relay without a driver. It usually consists of a led (transmitter) and a photoresistive receiver.

Speed of a stepper motor can be controlled by changing its switching speed or by changing the length of the time delay loop.

Torque is equal to the force applied at a particular distance. So its unit can be ounce-inch.

RPM rating given for a DC motor is for no-loaded condition.

 PWM allows the control of a DC moor with the same amplitude, but with different phases.

 The direction of the DC motor can be changed by changing the polarity of the voltages connected to its leads.