250+ TOP MCQs on Relay (Dual Channel) Module and Answers

Arduino Multiple Choice Questions on “Relay (Dual Channel) Module”.

1. What is the use of the Relay (Dual Channel) Module?
a) Monitors Motion
b) Evaluates air pressure
c) Monitors objects
d) Switches circuits
Answer: d
Calrification: The Relay (Dual Channel) Module is used for controlling a circuit by one signal or when many circuits must be controlled by one signal. Thus making it a primarily switching device.

2. How many pins are present in the Relay (Dual Channel) Module?
a) 12
b) 220
c) 13
d) 50
Answer: c
Calrification: The Relay (Dual Channel) Module has 13 pins which includes the 2 Vcc’s, 2 GND’s, IN1 and IN2 which are the two input channels, 2 NC’s, 2 NO’s and 2 COM’s. All these pins have very specific functions and input patterns which need to be connected in perfect order in order for the module to function properly.

3. What is the use of the IN1 and IN2 pin?
a) Input
b) Output
c) Ground
d) Power input
Answer: a
Calrification: The IN1 and IN2 respectively are used for sending digital inputs to the module. They accept 5V usually if the module has a 5V rating. Some modules also come with a 3.3V rating so it is important to check the rating of the module to be used.

4. What will happen if we supply a voltage of 250 kV to the Vcc of the Relay (Dual Channel) module?
a) Damage is caused
b) Module will shut down
c) Module will not respond for the time the voltage is applied
d) Module will function normally
Answer: a
Calrification: The Relay modules are mostly built to work on a voltage range of approximately 3.3V to 5V. Any voltage lower than that and the sensor will not be able to power on, but however any voltage significantly above that and the sensor may suffer permanent damage.

5. What is the use of the COM pin?
a) Input
b) Output
c) Ground
d) Circuit Completion
Answer: d
Calrification: The COM pin is used for completing the circuit such that the relay module can function fully when connected to the micro-controller. There are 2 COM pins, 1 for each channel.

6. What is the optimum current that is required to operate the Relay Module?
a) 28 A
b) 13 A
c) 210 A
d) 1 A
Answer: a
Calrification: The current rating on the Relay Module is given so that users can know what is the optimum current that needs to be fed to the module such that the internal electronics is not destroyed by excess current.

7. What kind of device is the Relay Module?
a) Passive Sensor
b) Active Sensor
c) Radio Device
d) Switching Device
Answer: d
Calrification: The Relay Module is a switching device since it’s primary function is to switch or change the direction of flow of current or stop it altogether. This way it controls the working of any given circuit.

8. What is the type of output given by the DC Relay Module?
a) Analog Signal
b) AC Signal
c) DC Signal
d) Hybrid Signal
Answer: c
Calrification: The Relay Module can switch current flow depending upon the rating of it. If the Relay Module has been rated for DC Usage then it should not be used for AC Circuits and vice-versa.

9. How much time does it take for the relay module to react to a change?
a) 5 to 10 ms
b) 12 to 10 min
c) 52 to 100 ms
d) 5 to 10 s
Answer: a
Calrification: 5 to 10 ms is the correct value of the time needed for the module to react to any command given to it by an external voltage source or micro-controller.

10. What happens to the NO1 and NO2 pins when INT1 and INT2 is HIGH?
a) Gets connected to COM
b) Gets disconnected from COM
c) Gets connected to Vcc
d) Gets connected to GND
Answer: b
Calrification: A disconnected COM port gives the correct value of the state of the NO1 and NO2 pins when 5V or logical HIGH signal is fed to the INT1 and INT2 pins. Conversely they also get connected to the COM when INT1 and INT2 pins are set to LOW.