Physics Units of Measurement - Physics Learning 4

Practice Physics Units of Measurement questions with answers. This prep guide includes questions like, define least count, how to calculate least count?, what is zero error?, what is least count of screw gauge?, is vernier caliper is more precise or screw gauge? and others below.

Physics Units of Measurement Learning 4

Question: Define least count

Answer: The smallest value up to which an instrument can measure is called least count. For example least count of meter rule is up to 1 mm and least count of Vernier caliper is 0.01 cm.

Question: How to calculate least count?

Answer: Least count = smallest division on main scale⁄ no. of divisions on Vernier scale so L.C = 1mm ⁄ 10 divisions = 0.1mm

Question: What is zero error?

Answer: It is a type of error in which an instrument gives a reading when the true reading at that time is zero. For example needle of ammeter failing to return to zero when no current flows through it.

Question: What is least count of screw gauge?

Answer: The smallest reading up to which a screw gauge can be measured is called least count of screw gauge. It can be find out by following method; L.C = pitch of screw gauge ⁄ no. of divisions on circular scale i-e 1mm⁄100 = 0.01 mm

Question: Is vernier caliper is more precise or screw gauge?

Answer: As compare to Vernier calipers, screw gauge is more precise because the least count of Vernier calipers is 0.1 mm and for screw gauge it is 0.01 mm. So, a screw gauge can measure more precisely than a Vernier caliper.