Measurements and Experimentation Solutions Exercise 1(B) — Very Short Answer Type

Ans: Least count of an instrument is the smallest measurement that can be taken accurately with it.

Ans: The least count can be decreased by:

• Increasing the number of divisions on the vernier scale
• Decreasing the value of one division on main scale

Ans: The difference between one main scale division and one vernier scale division. Also known as least count of vernier.

Ans: When zero marks of both scales coincide with jaws closed, and 10th vernier division aligns with 9th main scale division.

Ans:

• External diameter → Outside jaws
• Internal diameter → Inside jaws
• Depth → Strip
• Thickness → Outer jaws

Ans:

• Positive: Vernier zero right of main scale zero
• Negative: Vernier zero left of main scale zero

Ans: The linear distance moved by the screw on the main scale when the circular scale completes one full rotation.

Ans: Measuring diameter of thin wires or thickness of thin sheets.

Ans: To prevent over-tightening and ensure consistent pressure during measurements.

Ans:

• Positive: Circular scale zero below reference line
• Negative: Circular scale zero above reference line

Ans:

• Needle diameter → Screw gauge
• Paper thickness → Screw gauge
• Bottle neck → Vernier calipers
• Pencil diameter → Screw gauge

Ans: Screw gauge (0.01 mm accuracy)

Ans: