Which of the following operations involves straightening a curved sheet metal?

36) Which of the following is used for checking the external diameter of a cylindrical object?

37) What is the rolling resistance to the truck whose weight is 72,000 N and its co-efficient of rolling resistance is 0.019?

38) The electronic device that measures the proportion of oxygen (O2) in the gas or liquid is called

39) To which of the following categories does a petrol engine belong?