NEET-UG and JEE Main Physics · Class 12
Mass by the principle of moments — NEET & JEE Questions
Mass by the principle of moments is a topic in Experimental Skills, a Class 12 Physics chapter of the NEET-UG and JEE Main syllabus. TestBudy holds 14 published NEET-UG and JEE Main questions on Mass by the principle of moments, each with the marking scheme of the real paper.
- questions
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Mass by the principle of moments MCQs with solutions
10 of the 14 published questions on this topic, exactly as they appear in a test. Answers and worked solutions come with your result rather than on this page.
For a body in rotational equilibrium about a pivot, the algebraic sum of moments is
- A. zero
- B. equal to its mass
- C. always clockwise
- D. always anticlockwise
The moment of a force about a pivot equals
- A. force divided by distance
- B. force times perpendicular distance from the pivot to its line of action
- C. mass times length only
- D. force times parallel distance
In a simple balance experiment, an unknown mass m at distance x balances known mass M at distance y when
- A. m/x=M/y
- B. mM=xy
- C. mx=My
- D. m+y=M+x
A 200 g mass at 30 cm balances an unknown mass at 20 cm. The unknown mass is
- A. 133 g
- B. 200 g
- C. 450 g
- D. 300 g
For a beam in rotational equilibrium about a pivot, the principle of moments states that
- A. sum of clockwise moments equals sum of anticlockwise moments
- B. all forces must act at the pivot
- C. clockwise moments are always larger
- D. the beam must have zero mass
Why is it useful to choose the pivot as the moment reference?
- A. The pivot reaction has zero moment about the pivot
- B. Gravity disappears at the pivot
- C. all other forces become zero
- D. mass no longer has weight
A metre rule of non-negligible mass is used in a moments experiment. Its own weight acts effectively at
- A. the pivot always
- B. its centre of gravity
- C. the zero-cm mark always
- D. the heaviest attached mass
A 200 g mass is placed 30 cm from a pivot. At what distance on the opposite side should a 300 g mass be placed for equilibrium?
- A. 10 cm
- B. 20 cm
- C. 30 cm
- D. 45 cm
A 100 g standard mass balances an unknown mass when their distances from the pivot are 40 cm and 25 cm respectively. What is the unknown mass?
- A. 62.5 g
- B. 100 g
- C. 160 g
- D. 250 g
If the lever arm of an unknown mass is doubled while the balancing known mass and its arm are unchanged, the required unknown mass
- A. doubles
- B. quadruples
- C. halves
- D. is unchanged
Common mistakes in Mass by the principle of moments
Recorded against questions in this topic that are not shown above, so none of these points at an answer you can see on this page.
- Assumes a distance error cannot affect an inferred mass.
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