ACTIVITY No. 2 LAW OF MOMENTS

 

ACTIVITY No. 2

 LAW OF MOMENTS

Aim To determine the mass of a given body using a meter scale by principle of moments.

Apparatus A meter scale suspended at C.G., hanger with slotted weights, a body of unknown mass.

Diagram:

Mean mass=70 g

Result  The unknown mass of a body m1 = 70 g

Precaution: Find centre of gravity of scale using knife edge.

Quiz

MCQs

1. The principle of moments states that a body is in equilibrium when:

A. Clockwise moment = 0

B. Anti-clockwise moment = 0

C. Clockwise moment = Anti-clockwise moment

D. Weight = Mass

Answer: C

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2. Moment of a force is defined as:

A. Force × Area

B. Force × Distance from pivot

C. Mass × Acceleration

D. Weight × Time

Answer: B

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3. In the experiment, the meter scale acts as a:

A. Beam balance

B. Lever

C. Spring balance

D. Thermometer

Answer: B

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4. The point at which the meter scale balances horizontally without any load is its:

A. Centre of gravity

B. Pivot point

C. Moment arm

D. Zero error

Answer: A

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5. If a heavier body is placed on the meter scale, to balance it the known weight must be placed:

A. Closer to the fulcrum

B. Farther from the fulcrum

C. On the same side

D. On top of the heavier body

Answer: B

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6. The meter scale balances when:

A. Only the masses are equal

B. Only the distances are equal

C. Product of mass and distance on both sides is equal

D. The scale is vertical

Answer: C

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7. If W is the known weight, m is the unknown mass, d₁ is the distance of W from the pivot, and d₂ is the distance of m from the pivot, then the correct equation is:

A. W + m = d₁ + d₂

B. W × d₁ = m × d₂

C. W / d₁ = m / d₂

D. W − m = d₁ − d₂

Answer: B

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8. The fulcrum used in this experiment is typically a:

A. Meter scale

B. Knife edge

C. Spring

D. Clamp

Answer: B

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9. The mass of the given body is determined by measuring:

A. Only the distances

B. Only the time taken to oscillate

C. The balancing distances and using known mass

D. Electrical resistance

Answer: C

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10. When the meter scale tilts to one side, it indicates:

A. Thermal expansion

B. Unbalanced moments

C. Equal masses

D. Zero error

Answer: B