CBSE Questions for Class 8 Physics Force And Pressure Quiz 10 - MCQExams.com

Atmospheric pressure exerted on earth is due to the.
  • Gravitational pull
  • Revolution of earth
  • Rotation of earth
  • Uneven heating of earth
A 50 kg girl wearing heel shoes balances on a single heel. The heel is circular with a diameter 1 cm. The pressure exerted by the heel on the horizontal floor is then (Take g = 10 m s$$^{-2}$$)
  • 6.4 x 10$$^4$$ Pa.
  • 6.4 x 10$$^5$$ pa
  • 6.4 x 10$$^6$$ Pa
  • 6.4 x 10$$^7$$ Pa
Force acts on an object may change
  • Direction
  • Speed
  • Shape
  • All the above
Which of the following pairs of forces will never give resultant force of $$2N$$
  • $$2N$$ and $$2N$$
  • $$1N$$ and $$1N$$
  • $$1N$$ and $$3N$$
  • None of these
A wooden piece $$5\, N$$ in weight and $$5cm \times 3cm \times 2cm $$ in size lies on $$5cm \times 2cm$$ face. The pressure exerted by it in $$N\, per\, cm^2$$ is:
  • $$150$$
  • $$50$$
  • $$0.5$$
  • $$15$$
The three vessels shown in figure have same base area. Equal volumes of a liquid are poured in the three vessels. The pressure at the  base will be
1180712_042359e2b47d4428872dbaba93e20604.png
  • Maximum in vessel $$A$$
  • Maximum in vessel $$B$$
  • Maximum in vessel $$C$$
  • Equal in all the vessels

A force acts for 10s on a body of mass  $${10^{ - 2}}{\text{kg}}$$ initially at rest. Then after the force ceases to act. The body traverses 0.5m in next 5s. The magnitude of the force is 
  • $${10^{ - 1}}N$$
  • $${10^{ - 2}}N$$
  • $${10^{ - 3}}N$$
  • $${10^{ - 4}}N$$
Consider two shoulder bags, one with a thin strap, and the other with a wide strap. If both the bags are equally heavy, the bag with the wide strap will be more comfortable to carry because
  • the thin strap has greater inertia per unit length
  • the thin strap causes greater momentum to be exerted
  • the wide strap allows friction to be spread over a bigger area, thus reducing force between shoulder and the strap
  • the wide strap enables the weight of the bag to be spread over a bigger area, thus reducing the pressure on the shoulder.
Fill in the blanks.
At least _____________ objects must be present to experience a gravitational force. 
  • 1
  • 2
  • 3
  • 4
To move at the same speed, a car with a flat face and another with a streamlined body will require a different amount of force from the engine. The engine of the streamline bodied car will:
  • Exert less force
  • Exert more force
  • Exert zero force
  • Exert no force
Write true or false. Correct the false statements.
  • The perpendicular distance from the pivot of a rotating body to the line of known as the moment arm.
  • pressure is inversely proportional to the force applied
  • Wooden sleepers are placed under railway tracks in order to increase pres.
  • pressure is independent of the roughness of the surfaces in correct.
Three charges $$4q, Q$$ and q are in a straight line in the position of $$0, 1/2$$ and I respectively. The resultant force on q will be zero, if Q=
  • - q
  • $$-2q$$
  • $$-\frac{q}{2}$$
  • $$4q$$
A cube of edge length 5 cm is place inside a liquid. The pressure at the center of a face is 12 pa. Find the force exerted by the liquid on this face.
  • 0.03 N
  • 0.08 n
  • 0.06 n
  • 0.3 N
Consider the following two cases which involve the motion of an object
Case 1: An apple falling from a tree towards the ground.
Case 2: To move a loaded cart on the horizontal ground.
  • Case 1: Involves pushing of the apple by earth's gravitational force
  • Case 1: Involves pulling of apple by earth magnetic force
  • Case 2: Involves loaded cart to be moved by pulling force only
  • Case 2: Involves loaded cart to be moved by both pulling or pushing force
The force between two charge bodies is called 
  • muscular force
  • gravitational force
  • magnetic force
  • electrostatic force
When three forces of 50N, 30N and 15N act on a body, then the body is 
  • At rest
  • Moving with a uniform velocity
  • In equilibrium
  • Moving with an acceleration
Which of the following statements is /are true?
  • The  strength of a non contact force is independet of distance between the bodies.
  • Metecors that enter earth atmosphere burn up due to non-contact 
  • Magnet force is a non contact force
  • Contact  forces are always observes than non-contact forcs.

1745858_32969fb586074a1899d38ece954a7ba9.png
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
  • Assertion is correct but Reason is incorrect
  • Both Assertion and Reason are incorrect
A vehicle sinks into soft ground. The vehicle is changed so that it does not sink as far. Which change is made?
  • A lower centre of mass
  • A more powerful engine
  • Wheels that are further apart
  • Wider tyres
Select the correct alternative:
A force does not change.
  • Mass
  • Length
  • Shape
  • State of motion
State if the following statements are true or false. Correct the statement if it is false.
It is possible that a force applied to an object may not bring any change in it.
  • True
  • False
The non-contact force is :
  • Tension in string
  • Force of reaction
  • Force due to gravity
  • Force of the friction
A force is needed to :
  • Change the state of motion or state of rest of the body
  • Keep the body in motion
  • Keep the body stationary
  • Keep the velocity of body constant
Which of the following is a contact force:
  • Electrostatic force
  • Gravitational force
  • Frictional force
  • Magnetic force
Which of these is an example of a non-contact force?
  • A toy car slides down the ramp
  • A bar magnet moves a paperclip without touching it
  • A child lifts a book lying on the table
  • A marble rolling on the carpet slows down
Change in the state of rest or of uniform motion is brought about by:
  • Acceleration
  • Force
  • Energy
  • None
Anoop places a cuboid of dimensions $$12 cm \times 8 cm \times 6 cm$$ with different faces touching the table. Which face touching the table will have the greatest pressure exerted?
  • Cannot be said
A coin flicked across a table will stop. Why?
  • It is heavy.
  • No force is acting on it.
  • The Earth attracts the coin.
  • Table exerts a frictional force.
How could you place an empty bottle on a table so that it produces the greatest amount of pressure on the table?
283189_a655af7a1bb24420a2357ebbf134ed8a.png
  • Position $$1$$
  • Position $$2$$
  • Position $$3$$
  • All positions produce the same pressure.

Figure shows a siphon. The liquid is water. The beakers are open and the points A and B are at the surface of water, exposed to the air. The pressure difference $$P_B-P_A$$ between the points A and B



73719_f0d17fe2c09845cca9f6a28e1fb146b0.png
  • $$400 Nm^{-2}$$
  • $$3000 Nm^{-2}$$
  • $$1000 Nm^{-2}$$
  • Zero
0:0:1


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