## Physics Grade XI viva Question Vernier calliper

**1: What is vernier calipers?**

Ans. It is simple instrument by which length of an object can be measured accurately up to one-tenth of a millimeter or one-hundredth of a centimeter.

**2: What is the use of Vernier Scale?**

Ans. To increase the accuracy of the main scale.

**3: What is least count (L.C.)?**

Ans. The minimum measurement that can be taken by an instrument.

**4: What is the least count of?**

(a) meter scale (b) Stop Watch (c) Vernier Calliper

Ans. The least count of:

(a) meter scale = 0.1 cm or 1 mm.

(b) stop watch = 0.01 sec or 1/100 sec. or according to stop watch.

(c) vernier scale = 0.01 cm or 0.1 mm

**5: What are units of vernier scale?**

Ans. Vernier has not units of its own.

**6: What is the difference in the measurement of one smaller division on the main scale (M.S.) and that of vernier scale** (V.S.)

Ans. (1 smallest Div. on M.S.) – (1 smallest Div. on V.S) = 0.1 – 0.09 = 0.01 cm = Least count.

**7: How the L.C. of a vernier is determined?**

Ans. By using the relation:

L.C. = (Smallest division on Main Scale ) / (Total number of divisions on Vernier Scale)

**8: Will the accuracy of a vernier will increase or decrease if 20 divisions are made in the same length?**

Ans. The accuracy will increase since the L.C. will decrease i.e. Accuracy α = 1 / Least count

**9: Which one is smaller M.S. div. or V.S. div.?**

Ans. V.S. division.

10: 1 division on V.S. = _____ cm.

Ans. 0.09 cm.

10 div. on V.S. = 0.9 cm

1 div. on V.S. = 0.9/10 cm = 0.09 cm

**11: What are the functions of (a) Sliding strip (b) Upper jaws**

Ans. (a) For measuring depth. (b) For measuring the inner diameter.

**12: What is meant by zero error (Z.E.)?**

Ans. The error which arises when zeros of M.S. and V.S. do not coincide upon joining the two jaws.

**13: When Z.E. is positive**?

Ans. The Z.E. is positive when the zero of V.S. is to the right of the zero of M.S.

**14: How we find the corrected reading?**

Ans. Corrected reading = Meaning reading – ( + Z.E.)

**.15: Do you know any use of vernier scale?**

Ans. It is used in spectrometer, barometer, traveling microscope, etc.

**16: What are significant figures?**

Ans. Numbers 0, 1, 2, 3, ……. are called significant figures when they occur. The zero is not a significant figure if it is at the extreme left or extreme right of a number, e.g. 1.02 has three significant figures, but 1.20 has two significant figures.

**17: What is meant by degree of accuracy?**

Ans. It is the measurement estimated by the number of significant figures in the result.

**18: Why is the vernier calipers so called?**

Ans. A French mathematician named Pierre Vernier invented it and it is named after him.

**19: How does temperature affect the length of a cylinder?**

Ans. The length of a cylinder increases with the increase of temperature and decreases with the

decrease of temperature.

**20: What is the unit of volume?**

Ans. In MKS system, the unit of volume is m3. In CGS system, the unit of volume is cm3. In FPS

system, the unit of volume is ft3.

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