CBSE Class 8 - Science - Force, Pressure and Friction (Multiple Choice Questions)(#eduvictors)(#cbseClass8Science)

Force, Pressure and Friction 
(Multiple Choice Questions)

CBSE Class 8 - Science

Q1. Force on an object
  (a) must change the speed of the object if it is moving.
  (b) may change the direction of motion.
  (c) must change the shape of object. .
  (d) none of these


Q2. Strength of a force is expressed by 
   (a) Magnitude
   (b) Direction
   (c) Both magnitude and direction
   (d) none of these

3. Force of friction is
   (a) contact force
   (b) non-contact force
   (c) gravitational force
   (d) electrostatic force



Q4.  Pressure excreted by a liquid on the walls of a container depends upon
  (a) size of container
  (b) height of liquid
  (c) shape of container
  (d) none of these


Q5. Sliding friction
  (a) is smaller than static friction.
  (b) is greater than static friction.
  (c) is equal to static friction. |
  (d) is smaller than rolling friction.


Q6. Frictional force on an object in a fluid depends upon
 (a) its speed with respect to the fluid.
 (b) shape of the object
 (c) nature of the fluid
 (d) all of the above


Q7. In the arrangement given below, which arrangement of forces due to friction is in increasing order:
 (a) rolling, static, sliding
 (b) rolling, sliding, static
 (c) static, sliding, rolling
 (d) sliding, static, rolling


Q8. Which of the following is a contact force?
 (a) electrostatic force
 (b) gravitational force
 (c) magnetic force
 (d) frictional force :


Q9. Which of the following is always attractive force?
 (a) electrostatic force
 (b) gravitational force
 (c) magnetic force
 (d) frictional force :


Q10: Gravity is the property of the earth alone?
(a) True
(b) False


Answers:
1: (b) may change the direction of motion.
(Note: the word 'may'. It is not necessary, force will always bring change in speed or direction.)

2:    (c) Both magnitude and direction

3:    (a) contact force

4:   (b) height of liquid
Note: Pressure in liquid is directly proportional to the depth of an immersed object, and the pressure at the same depth is different in different liquids when their densities are different. However, when the type of liquid and depth remain constant, the shape of a container does not affect pressure in liquids.

5:   (a) is smaller than static friction.

6:  (d) all of the above

7: (b) rolling, sliding, static

8:  (d) frictional force :

9: gravitational force

10: (b) False

☞See also:
Ch 11 - Force and Pressure (Q & A)
Ch11 - Force and Pressure (MCQs)
Ch 11 - Force (What is Inertia?)
Ch 11 - Force and Pressure (Assignment Sheet)
Ch 11 - Force and Pressure (Worksheet)
Force, Pressure and Friction (Q & A)

Ch 12 - Friction
Ch 12 - Friction (MCQs-1)
Ch 12 - Friction (MCQs-2)
Ch12 - Friction (Assignment)
Ch 12 - Friction (Worksheet)
Ch 12 - Friction (Worksheet-2018-19)