# WBBSE Class 9 Physical Science MCQ Questions Chapter 3 Matter: Structure and Properties

Well structured WBBSE Class 9 Physical Science MCQ Questions Chapter 3 Matter: Structure and Properties can serve as a valuable review tool before exams.

## Matter: Structure and Properties Class 9 WBBSE MCQ Questions

Multiple Choice Questions :

Question 1.
atmospheric pressure is measured by :
(i) hygrometer
(ii) pyrometer
(iii) Barometer
(iv) spherometer
Barometer

Question 2.
Construction of a submarine is based on :
(i) Archimedes’ principle
(ii) Bernoulli’s theorem
(iii) Pascal’s law
(iv) Boyle’s law
Archimedes’ principle

Question 3.
Why is the dam of water reservoir is thick at the bottom?
(i) quantity of water increases with depth
(ii) density of water increases with depth
(iii) pressure of water increases with depth.
(iv) temperature of water increases with depth.
The pressure of water increases with depth.

Question 4.
A wooden block is taken to the bottom of a deep, calm lake and then released. it rises up with a :
(i) constant acceleration
(ii) decreasing acceleration
(iii) constant velocity
(iv) decreasing velocity
Constant acceleration

Question 5.
A capillary tube made of glass is dipped into mercury. Then
(i) mercury rises in the capillary tube
(ii) mercury falls in the capillary tube
(iii) mercury rises and flows out of capillary tube
(iv) mercury neither rises nor falls in the capillary tube
Mercury falls in the capillary tube

Question 6.
If the diameter of a capillary tube be doubled then the height of the liquid that will rise is :
(i) twice
(ii) half
(iii) same as earlier
(iv) none of these.
Half

Question 7.
Two pieces of glass plates one upon the other with a little water in between them cannot be separated easily because of :
(i) inertia
(ii) pressure
(iii) surface tension
(iv) viscosity
Surface tension

Question 8.
There is dip in the capillary tube when the angle of contact θ is :
(i) θ = 90°
(ii) θ = 0°
(iii) θ > 90°
(iv) θ < 90° but not zero
θ < 90° but not zero

Question 9.
The rise of liquid in a capillary tube has a meniscus. If the angle of contact be 90°, the shape of the meniscus is :
(i) concave
(ii) convex
(iii) flat
(iv) none of the above
Flat

Question 10.
In Bernoulli’s theorem, which of the following is conserved ?
(i) mass
(ii) linear momentum
(iii) energy
(iv) angular momentum
Energy

Question 11.
The gale blows over a house. The force due to gale on the roof is :
(i) in the direction downward
(ii) in direction upward
(iii) zero
(iv) in the horizontal direction.
In direction upward

Question 12.
To calculate the flow of a liquid, which of the following is used?
(i) Stoke’s law
(ii) Bernoulli’s theorem
(iii) Poiseuille’s law
(iv) Conservation of pressure
Poiseuille’s law

Question 13.
Scent sprayer is based on :
(i) Charles’s law
(ii) Archimedes’ principle
(iii) Boyle’s law
(iv) Bernoulli’s theorem.
Bernoulli’s theorem

Question 14.
In old age arteries carrying blood in the human body become narrow resulting in an increase in the blood pressure. This follows from
(i) Pascal’s law
(ii) Stoke’s law
(iii) Bernoullis’ principle
(iv) Archimede’s principle
Bernoulli’s principle

Question 15.
On which of the following the terminal velocity of a solid ball in a viscous fluid is independent?
(i) area of cross-section
(ii) height of the liquid
(iii) density of the both
(iv) density of the liquid
Height of the liquid

Question 16.
A body of weight mg is hanging on a strain, which extends its length by 1. The work done in extending the string is :
(i) mgl
(ii) mgl / 2
(iii) 2 mgl
(iv) none of these
mgl / 2

Question 17.
According to Hooke’s law of elasticity, if stress is increased the ratio of stress to strain :
(i) increases
(ii) decreases
(iii) becomes zero
(iv) remains constant
Remains constant

Question 18.
S.I. unit of pressure is
(i) pascal
(ii) Kgfm-2
(iii) atmosphere
(iv) none of these
pascal

Question 19.
upthrust depends upon –
(i) volume
(ii) density
(iii) g
(iv) all of these
all of these

Question 20.
If the density of the object placed in a liquid to the density of the liquid, the object will –
(i) float wholly immersed
(ii) float half immersed
(iii) sink
(iv) float completely above the liquid
float wholly immersed

Question 21.
Atmospheric pressure is measured by –
(i) hydrometer
(ii) barometer
(iii) sonometer
(iv) ammeter
barometer.

Question 22.
Relative density s of a substance is related to the density of the substance ρ and density of water at 40C d as –
(i) s = ρ × d
(ii) $$\mathrm{s}=\frac{d}{\rho}$$
(iii) $$\frac{\rho}{d}$$
(iv) $$\frac{1}{\rho d}$$
$$\frac{\rho}{d}$$

Question 23.
SI unit of surface tension is
(i) Nm
(ii) kgfm-1
(iii) mN-1
(iv) Nm-1
Nm-1

Question 24.
The terminal velocity of a spherical body depends on
(ii) density of the medium
(iii) viscosity of the medium
(iv) all of these
all of these

Question 25.
Bernoulli’s theorem is based on conservation of –
(i) mass
(ii) mass and energy
(iii) energy
(iv) none of these
energy.

Question 26.
With increase in temperature, the elasticity of a material
(i) increases
(ii) decreases
(iii) remains unchanged
(iv) nothing can be said
decreases

Question 27.
The solids if break soon after crossing elastic limit are called
(i) ductile
(ii) brittle
(iii) malleable
(iv) plastic
brittle

Fill in the blanks :

1. The word fluid comes from a Latin word _______.
Fluere (meaning ‘to flow’)

2. The branch of physics which deals with fluid at rest is called _______.
Hydrostatics

3. The branch of physics which deals with fluid in motion is called _______.
Hydrodynamics

4. Specific gravity of a substance is the ratio of the density of a substance to the density of _______ at 4°C.
Water

5. In CGS system, the density of a substance is numerically _____ its specific gravity.
Equal

6. The unit of pressure in SI is ______.
Pascal (Nm-2)

7. The liquid pressure is a ______ quantity.
Scalar

8. Archimede’s principle does not hold when the body is in ______ condition.
Weightless

9. When the weight of the body is greater than the weight of the liquid displaced, then the body ______.
Sinks

10. Condition of floatation of a body is such, that the weight of the floating body must be ______ to the weight of the liquid dispiaced.
Equal

11. If the density of the body be equal to the density of the liquid, the body ______ completely immersed any where in the liquid.
Floats

12. The height of a water barometer is ______.
10.33 m

13. The forces between the molecules of substances are called ______ forces.
Inter-molecular

14. The unit of surface tension in SI system is : ______.
Newton per metre (Nm-1)

15. Rain drops attain ______ shape to acquire minimum surface area.
Spherical

16. A tube with a very fine uniform bore throughout its length called a ______ tube.
Capillary

17. A towel soaks water on account of ______ action.
Capillary

18. Antiseptics have very ______ surface tension, so that can spread quickly.
Low

19. The relative viscosity of a liquid is the ratio of viscosity of a liquid to viscosity of ______.
Water

20. The terminal velocity of a sphere varies directly as the square of the ______ of it.

21. The viscosity of a liquid ______ with increase in temperature.
Decreases

22. Reynold’s number is the ratio of the inertial force per unit area to ______ force per unit area for a flowing iluid.
Viscous

23. The deep water runs ______ in a river.
Slow

24. The dimensional formula of stress is ______.
[ML-1 T-2]

25. The fractional change in the length, volume or shape of a body relative to that in its original configuration is a measure of the ______.
Strain

26. The deformation of an elastic body is directly proportional to the applied force within ______ limit.
Elastic

27. The normal force exerted by fluid on any surface in contact with its, called ______.
thrust

28. The liquid ______ its own level.
finds

29. A ______ is an instrument for measuring the pressure of the atmosphere.
barometer.

30. A siphon acts under ______ pressure.
Ans,
atmospheric

31. The upward thrust which any fluid exerts upon a body partly or completely immersed in it, is called its ______.
buoyancy

32. Relative density is a pure ______ having no unit.
number

33. Surface tension is a ______ quantity.