Mass

Mass is defined as:
a) Force acting on a body
b) Amount of matter in a body
c) Speed of a body
d) Weight of a body
✅ b) Amount of matter in a body
Explanation: Mass is the measure of matter in an object.

SI unit of mass is:
a) Gram
b) Newton
c) Kilogram
d) Pound
✅ c) Kilogram
Explanation: Kilogram (kg) is the SI base unit of mass.

Which of the following is a scalar quantity?
a) Mass
b) Velocity
c) Force
d) Acceleration
✅ a) Mass
Explanation: Mass has magnitude only, no direction.

Which instrument is used to measure mass directly?
a) Spring balance
b) Beam balance
c) Thermometer
d) Barometer
✅ b) Beam balance
Explanation: Beam balance compares an unknown mass to a known mass.

1 kilogram = how many grams?
a) 10 g
b) 100 g
c) 1000 g
d) 10,000 g
✅ c) 1000 g
Explanation: Kilo means 1000, so 1 kg = 1000 g.

Which of the following is NOT a unit of mass?
a) Tonne
b) Pound
c) Newton
d) Gram
✅ c) Newton
Explanation: Newton is the unit of force (i.e., weight), not mass.

Mass of a body on the Moon is:
a) Zero
b) One-sixth of Earth
c) Same as on Earth
d) Doubled
✅ c) Same as on Earth
Explanation: Mass is constant, irrespective of gravity.

What is the mass of an object that weighs 98 N on Earth?
a) 9.8 kg
b) 10 kg
c) 98 kg
d) 100 kg
✅ b) 10 kg
Explanation: W = mg → m = W/g = 98/9.8 = 10 kg.

What happens to mass when an object is taken to space?
a) Increases
b) Decreases
c) Becomes zero
d) Remains constant
✅ d) Remains constant
Explanation: Mass does not depend on gravity.

Traditional Indian unit of mass is:
a) Litre
b) Cubit
c) Seer
d) Furlong
✅ c) Seer
Explanation: 1 seer ≈ 0.933 kg; used in traditional Indian markets.

The inertia of a body is directly related to its:
a) Temperature
b) Mass
c) Velocity
d) Volume
✅ b) Mass
Explanation: Higher the mass, greater the inertia.

Which is heavier?
a) 1000 g of cotton
b) 1 kg of lead
c) Both same
d) Cannot say
✅ c) Both same
Explanation: 1000 g = 1 kg, regardless of volume or density.

Which quantity is used in Newton’s second law?
a) Volume
b) Force
c) Mass
d) Speed
✅ c) Mass
Explanation: F = ma → Force = mass × acceleration.

What is the mass of 1 mole of water (H₂O)?
a) 18 g
b) 36 g
c) 9 g
d) 1 g
✅ a) 18 g
Explanation: 2 hydrogen + 16 oxygen = 18 g/mol.

Mass is measured using:
a) Watt
b) Ampere
c) Balance
d) Voltmeter
✅ c) Balance
Explanation: Beam and electronic balances are used.

1 quintal =
a) 10 kg
b) 100 kg
c) 1000 kg
d) 1 tonne
✅ b) 100 kg
Explanation: Used in agriculture and markets.

Which of the following changes with gravity?
a) Mass
b) Weight
c) Volume
d) Density
✅ b) Weight
Explanation: Mass remains same, weight depends on gravity.

Which of the following is the smallest unit of mass?
a) Gram
b) Milligram
c) Microgram
d) Tonne
✅ c) Microgram
Explanation: 1 µg = 10⁻⁶ g.

Mass of an electron is:
a) 9.1 × 10⁻³¹ kg
b) 1.6 × 10⁻¹⁹ C
c) 0.1 kg
d) Zero
✅ a) 9.1 × 10⁻³¹ kg
Explanation: Fundamental constant in physics.

What is the CGS unit of mass?
a) Gram
b) Kilogram
c) Dyne
d) Newton
✅ a) Gram
Explanation: CGS = Centimetre–Gram–Second system.

1 tonne equals:
a) 100 kg
b) 1000 kg
c) 10,000 kg
d) 500 kg
✅ b) 1000 kg
Explanation: Used for large-scale goods.

Unit of mass in FPS system:
a) Kilogram
b) Pound
c) Newton
d) Tonne
✅ b) Pound
Explanation: FPS = Foot–Pound–Second system.

Which is not used to measure mass?
a) Spring balance
b) Beam balance
c) Analytical balance
d) Triple beam balance
✅ a) Spring balance
Explanation: Spring balance measures weight (force), not true mass.

The kilogram is now defined using:
a) Prototype cylinder
b) Platinum block
c) Planck constant
d) Gravitational constant
✅ c) Planck constant
Explanation: Since 2019, kg is defined by fixing the Planck constant.

Unit of atomic mass is:
a) Gram
b) Dalton
c) Joule
d) Newton
✅ b) Dalton
Explanation: 1 amu = 1 Dalton = 1.66 × 10⁻²⁷ kg.

The instrument for precise measurement of small masses is:
a) Vernier caliper
b) Screw gauge
c) Analytical balance
d) Barometer
✅ c) Analytical balance
Explanation: Measures down to milligrams or less.

If two bodies have same mass, then:
a) Their volume must be same
b) Their weight must be same
c) Their inertia is same
d) They must be same material
✅ c) Their inertia is same
Explanation: Inertia is mass-dependent.

Mass of a neutron is approximately:
a) Same as proton
b) Half of electron
c) Zero
d) Twice of proton
✅ a) Same as proton
Explanation: Mass of neutron ≈ 1.675 × 10⁻²⁷ kg.

What is the unit of mass used in gold trade?
a) Pound
b) Kilogram
c) Carat
d) Tola
✅ d) Tola
Explanation: 1 tola ≈ 11.66 g.

Mass can be measured in space using:
a) Spring balance
b) Beam balance
c) Inertial balance
d) Thermometer
✅ c) Inertial balance
Explanation: Measures mass using oscillation period.

The ratio of weight to mass gives:
a) Velocity
b) Pressure
c) Gravity
d) Energy
✅ c) Gravity
Explanation: g = W/m.

The mass of 1 mole of oxygen (O₂) is:
a) 8 g
b) 16 g
c) 32 g
d) 64 g
✅ c) 32 g
Explanation: O₂ = 16 × 2 = 32 g/mol.

A 5 kg mass is taken to the Moon. Its mass becomes:
a) 0.83 kg
b) 1 kg
c) 5 kg
d) Zero
✅ c) 5 kg
Explanation: Mass is constant everywhere.

Unit of mass used in pharmacy:
a) Microgram
b) Kilogram
c) Newton
d) Pound
✅ a) Microgram
Explanation: Drug doses are often in micrograms or milligrams.

Mass of a body depends on:
a) Shape
b) Volume
c) Material
d) All of these
✅ d) All of these
Explanation: Mass = density × volume.

Which of the following has the largest mass?
a) 1 kg iron
b) 1 kg gold
c) Both same
d) Depends on volume
✅ c) Both same
Explanation: Mass is same, even if density differs.

On what does inertia of rest depend?
a) Weight
b) Temperature
c) Mass
d) Gravity
✅ c) Mass
Explanation: More mass = more inertia.

Unit used to express mass of nuclei:
a) Coulomb
b) Amu
c) Newton
d) Calorie
✅ b) Amu
Explanation: Amu = atomic mass unit.

An object of greater mass has:
a) Greater acceleration
b) Lower inertia
c) Greater inertia
d) Lower energy
✅ c) Greater inertia
Explanation: Heavy objects resist motion changes more.

Which is used in scientific lab balances?
a) Lever