Question

Hello friends

How does the lie detector machine used by Police and higher authorities work?

What's the principal behind the machine?

Kindly Don't spam

Answer 1

Y­ou hear about lie detectors all the time in police investigations, and sometimes a person applying for a job will have to undergo a polygraph test (for example, certain government jobs with the FBI or CIA require polygraph tests). The goal of a lie detector is to see if the person is telling the truth or lying when answering certain questions.

When a person takes a polygraph test, four to six sensors are attached to him. A polygraph is a machine in which the multiple ("poly") signals from the sensors are recorded on a single strip of moving paper ("graph"). The sensors usually record:

The person's breathing rateThe person's pulseThe person's blood pressureThe person's perspiration

Sometimes a polygraph will also record things like arm and leg movement.

Answer 2

Hey mate here's your answer......

A lie detector machine is an important machine in the Police department to catch the criminals , they question and check the answers and the machine helps to detect whether the person is lying or not .


A lie detector machine is known as polygraph , it measures and records the blood pressure , heart rate , pulse and skin conductivity for proper results.

Hope it helps ☺️