Measurements and Experimentation Solutions

03/05/2025 One Mark Solution Uncategorized 0

Measurements and Experimentation | Class 9 – Concise Physics Selina Solutions

Exercise 1(B) — Multiple Choice Type

1. Least count of metre rule having 10 subdivisions in 1 cm is:

  • a) 0.01 mm
  • b) 1 mm
  • c) 0.001 mm
  • d) 1 cm
Answer: b) 1 mm Least count = 1 cm ÷ 10 divisions = 1 mm per division

2. The least count of a vernier callipers is:

  • a) 1 cm
  • b) 0.001 cm
  • c) 0.1 cm
  • d) 0.01 cm
Answer: d) 0.01 cm LC = 1 main scale division (1 mm) ÷ 10 vernier divisions = 0.1 mm = 0.01 cm

3. The strip of a vernier callipers is used to measure:

  • a) Length of a wire
  • b) Depth of a beaker
  • c) Internal diameter of a sphere
  • d) Diameter of a hollow sphere
Answer: b) Depth of a beaker The depth measuring strip extends perpendicularly from the main scale

4. When jaws are closed, 6th vernier division coincides with main scale. If LC is 0.01 cm, zero error is:

  • a) +0.06 cm
  • b) +0.6 cm
  • c) +0.006 cm
  • d) +0.001 cm
Answer: a) +0.06 cm Zero error = +6 × LC = 6 × 0.01 cm = +0.06 cm

5. A microscope has main scale with 20 divisions/cm and vernier with 25 divisions equal to 24 main divisions. Least count is:

  • a) 0.002 cm
  • b) 0.001 cm
  • c) 0.02 cm
  • d) 0.01 cm
Answer: a) 0.002 cm LC = (1/20 cm) ÷ 25 = 1/500 cm = 0.002 cm

6. The correct use of the thimble in a screw gauge is to:

  • a) Read measurements up to 0.01 mm
  • b) Read measurements up to 1 mm
  • c) Mark main scale reference
  • d) Mark circular scale divisions
Answer: d) Mark circular scale divisions The thimble rotates and contains the circular scale markings

7. The ratchet is a component of:

  • a) Vernier callipers
  • b) Slide callipers
  • c) Screw gauge
  • d) None of these
Answer: c) Screw gauge Ratchet prevents excessive pressure on the measured object

8. The diameter of a thin wire can be measured by:

  • a) Vernier callipers
  • b) Metre rule
  • c) Screw gauge
  • d) None of these
Answer: c) Screw gauge Screw gauge provides required precision (0.01 mm) for thin wires

9. A screw gauge’s head has 50 divisions and moves 1 mm in 2 revolutions. Its pitch is:

  • a) 0.05 cm
  • b) 0.001 cm
  • c) 0.5 cm
  • d) 0.01 cm
Answer: a) 0.05 cm Pitch = 1 mm ÷ 2 revolutions = 0.5 mm = 0.05 cm

10. Correct ascending order of measurement accuracy:

  • a) Metre rule, Vernier, Screw gauge
  • b) Vernier, Metre rule, Screw gauge
  • c) Screw gauge, Vernier, Metre rule
  • d) None of these
Answer: a) Metre rule, Vernier, Screw gauge Accuracy: Metre (0.1 cm) < Vernier (0.01 cm) < Screw (0.001 cm)

Exercise 1(A) — Multiple Choice Type

Exercise 1(A) — Very Short Answer Type

Exercise 1(A) — Short Answer Type

Exercise 1(A) — Numericals

Exercise 1(B) — Multiple Choice Type

Exercise 1(B) — Very Short Answer Type

Exercise 1(B) — Short Answer Type

Exercise 1(B) — Long Answer Type

Exercise 1(B) — Numericals

Exercise 1(C) — Multiple Choice Type

Exercise 1(C) — Very Short Answer Type

Exercise 1(C) — Short Answer Type

Exercise 1(C) — Long Answer Type

Spread the love

Be the first to comment

Leave a Reply

Your email address will not be published.


*