Question

What is the difference between type A and type B?

(a) Least count is 5’ in type A and 10’ in type B

(b) Type A is provided with fine adjustment device whereas type B is not

(c) Type B is provided with fine adjustment device whereas type A is not

(d) The vernier scale is different in both types

The question was posed to me in an online interview.

The question is from Vernier and Optical Bevel Protractor in section Angular Measurement and Circular Division of Engineering Metrology

Answer 1

Right answer is (b) Type A is provided with fine adjustment device whereas type B is not

To elaborate: The difference between type A and Type B is that type A has a fine adjustment device or acute angle attachment whereas type B is not. The scales of all the types of mechanical bevel protractor are graduated either as semicircle marked 0—90—0 with two verniers 180° apart or as a full circle.