Question

The speedometer of a car measures
A. average speed
B. average velocity
C. instantaneous speed
D. instantaneous velocity

Answer 1

The instrument which measures the speed of a moving body (generally, automobile) is known as Speedometer. It is attached with an additional device known as an odometer that records the distance travelled by the vehicle. In this question, we need to comment on the speedometer of the car and what it measures.

Complete step by step answer:
The basic design of the speedometer is an analog instrument where the pointer of the speedometer may take up any position on the scale and sweeps through every value from zero to full scale as the car accelerates from rest to full speed. However, now-a-days digital speedometers are extensively used in the market.An analog representation is the measured quantity (in this case, speed) which is converted into another physical quantity (pointer
position) in a continuous way that means the value of the measured quantity is continuously represented by the value of the analogue, and no minimum change or step is required in the measured quantity to cause a change in its analogue. At any moment, the amount by which the pointer has moved from zero is said to be an `analog’ of the speed of the car. This measurement is at a particular moment, or you can say at a particular instant; hence the speedometer measures the instantaneous speed of the car or other vehicles.
Hence, option (C) is correct.

Note: A speedometer is a gauge that measures and displays the instantaneous speed of a vehicle. The speed is defined as the total distance travelled by a body divided by the total time.