What does allowance represent in clearance fits?

The study of scientific metrology deals with

A. accuracy and methods of measurement

B. standard specifications

C. theories related to nature

D. all of the above

Which of the following processes is used to monitor space signals of a space craft?

A. Stroboscope

B. Telemetry

C. Pyrometer

D. None of the above

Which of the following is not a type of direct measuring instrument?

A. micrometer

B. vernier caliper

C. divider

D. All of the above

Johansson mickrocator is a type of

A. mechanical optical comparator

B. mechanical comparator

C. optical comparator

D. electrical comparator

Which of the following statements are true? 1. Mechanical comparators are compact and easy to handle 2. Parallax error is never observed in mechanical comparator 3. Sigma comparator is a type of mechanical comparator 4. Mechanical comparators have low inertia which makes them sensitive to vibrations

A. 1 and 2

B. 3 and 4

C. 1 and 3

D. All of the above