Question

what are the devices that acts as accelerator and decelerator among cars?​

Answer 1

What is the function of accelerator in a car?

The throttle, which controls fuel and air supply to the engine and is also known as the "accelerator" or "gas pedal", is normally the right-most floor pedal. It has a fail-safe design – a spring, which returns it to the idle position when not depressed by the driver.