Correct Measurement of Length

We have to avoid taking readings from the _____ mark of the ruler if it is damaged. 

Choose the most appropriate option from the choices given below:

(zero / middle / ten)

What is a parallax error? How it can be avoided during the measurement of length?

During the measurement of length, the ruler should be placed perpendicular to the object to be measured.

List the precautions that should be taken during the measurement of length.

What precautions should you take while using a scale to measure length?

List the precautions that should be taken while measuring the length of an object using a scale.

List the precautions which need to be taken while measuring length using a ruler.

There are different means of measuring the length such as scale, metre rod and measuring tape. The choice of measuring device to be used depends upon the shape and size of the object to be measured. While using a scale to measure the length of an object, the eye should be correctly positioned. It should be just vertically above the required mark of the scale, otherwise wrong result would be obtained.

Rohit is measuring the length of a pencil using a scale. Praveen saw that Rohit's eye is not correctly positioned. He tells Rohit to keep his eye vertically just above the required mark of the scale.

What kind of value did Praveen show?

Which of the following units is used to measure length currently?

The correct position of the eye for taking a correct measurement in the given picture is: