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Gravitation — Class 9 CBSE Science MCQs with Solutions
Free Class 9 CBSE Science Gravitation MCQs with step-by-step solutions. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — easy
Universal Law of Gravitation was formulated by:
A. Galileo Galilei
B. Sir Isaac Newton ✓ Correct
C. Johannes Kepler
D. Albert Einstein
Solution: Newton formulated the Universal Law of Gravitation.
Q2 — easy
Gravitational force between two point masses m₁ and m₂ separated by distance r is proportional to:
A. (m₁ + m₂)/r
B. (m₁ × m₂)/r² ✓ Correct
C. (m₁ × m₂)/r
D. r²/(m₁ × m₂)
Solution: F = G(m₁m₂)/r².
Q3 — easy
Standard acceleration due to gravity (g) near Earth's surface is approximately:
A. 6.67 m/s²
B. 9.8 m/s² ✓ Correct
C. 1.63 m/s²
D. 100 m/s²
Solution: g ≈ 9.8 m/s² on Earth's surface.
Q4 — easy
Acceleration due to gravity on Moon's surface is about _______ of that on Earth.
A. 1/2
B. 1/6th ✓ Correct
C. 1/10th
D. Double
Solution: Lunar gravity g_moon ≈ g_earth / 6 ≈ 1.63 m/s².
Q5 — easy
Mass of a body is a scalar quantity measured in kg. Weight of a body is a force measured in:
A. Kilograms (kg)
B. Newtons (N) ✓ Correct
C. Joules (J)
D. Watts (W)
Solution: Weight W = m·g is a gravitational force vector measured in Newtons (N).
Q6 — easy
Force acting perpendicularly on a surface area is called:
A. Pressure
B. Thrust ✓ Correct
C. Friction
D. Tension
Solution: Thrust is the perpendicular force acting on a surface.
Q7 — easy
Pressure is defined as thrust per unit area. SI unit of pressure is Pascal (Pa), equal to:
A. 1 N·m
B. 1 N/m² ✓ Correct
C. 1 kg/m³
D. 1 J/m²
Solution: 1 Pascal = 1 N/m².
Q8 — easy
Upward buoyant force exerted by a fluid on an immersed object is called:
A. Viscosity
B. Buoyancy / Upthrust ✓ Correct
C. Surface tension
D. Gravity
Solution: Buoyant force acts upward against gravity.
Q9 — easy
Archimedes’ Principle states that when a body is immersed fully or partially in a fluid, upward buoyant force equals weight of:
A. Immersed body
B. Fluid displaced by the body ✓ Correct
C. Container
D. Air above
Solution: Upthrust = Weight of fluid displaced.
Q10 — easy
Relative Density of a substance is the ratio of its density to density of:
A. Air
B. Water at 4°C ✓ Correct
C. Mercury
D. Alcohol
Solution: Relative Density = Density of substance / Density of water.
Q11 — easy
If density of an object is LESS than density of liquid, the object will:
A. Sink
B. Float on liquid surface ✓ Correct
C. Dissolve
D. Evaporate
Solution: Objects less dense than fluid float.
Q12 — easy
Sharp knives cut vegetables easily because smaller cutting edge area produces:
A. Smaller pressure
B. Greater pressure ✓ Correct
C. Smaller force
D. Zero thrust
Solution: Pressure = Force / Area. Smaller area creates larger pressure.
Q13 — easy
Acceleration due to gravity g is maximum at Earth's _______ and minimum at _______.
A. Equator, Poles
B. Poles, Equator ✓ Correct
C. Center, Surface
D. Surface, Center
Solution: Earth's equatorial bulge makes g maximum at poles and minimum at equator.
Q14 — medium
Value of Universal Gravitational Constant G is:
A. 9.8 m/s²
B. 6.673 × 10⁻¹¹ N·m²/kg² ✓ Correct
C. 6.67 × 10¹¹ N·m²/kg²
D. 9.8 N/kg
Solution: G = 6.673 × 10⁻¹¹ N·m²/kg².
Q15 — medium
Weight of an object of mass 10 kg on Earth's surface is: (g = 9.8 m/s²)
A. 10 N
B. 98 N ✓ Correct
C. 98 kg
D. 1.63 N
Solution: W = m × g = 10 × 9.8 = 98 N.