Students can practice the best Class 8 Science MCQ and Exploring Forces Class 8 Science Curiosity Chapter 5 MCQ Online Test with Answers for exam preparation.
Class 8 Science Chapter 5 Exploring Forces MCQ
Exploring Forces MCQ
Class 8 Science Chapter 5 MCQ Online Test
Question 1.
In figure, two boys A and B are shown applying force on a block. If the block moves towards the right, which one of the following statements is correct? (NCERT Exemplar)
(a) Magnitude of force applied by A is greater than that of B.
(b) Magnitude of force applied by A is smaller than that of B.
(c) Net force on the block is towards A.
(d) Magnitude of force applied by A is equal to that of B.
Answer:
(a) Magnitude of force applied by A is greater than that of B.
Question 2.
The SI unit of weight is
(a) kilogram
(b) newton
(c) gram
(d) metre
Answer:
(b) newton
Question 3.
Which one of the following forces is a contact force? (NCERT Exemplar)
(a) Force of gravity
(b) Force of friction
(c) Magnetic force
(d) Electrostatic force
Answer:
(b) Force of friction
Question 4.
Which of the following will experience greater friction?
(a) A dry floor
(b) A wet, smooth floor
(c) A polished glass surface
(d) Oiled steel surface
Answer:
(a) A dry floor
Question 5.
During dry weather while combing hair, sometimes we experience hair flying apart. The force responsible for this is (NCERT Exemplar)
(a) force of gravity
(b) electrostatic force
(c) force of friction
(d) magnetic force
Answer:
(b) electrostatic force
Question 6.
A magnetic force can act on
(a) plastic objects
(b) wooden blocks
(c) iron nails
(d) rubber balls
Answer:
(c) iron nails
Question 7.
You place a book on a table. The book doesn’t fall because
(a) no force acts on it
(b) only gravity pulls it down
(c) upward force by table balances gravity
(d) the book is weightless
Answer:
(c) upward force by table balances gravity
Question 8.
Why does a ball thrown upwards return to the ground?
(a) Due to wind resistance
(b) Because its speed is high
(c) Due to magnetic force
(d) Due to gravitational force
Answer:
(d) Due to gravitational force
Question 9.
Which of the following statements is true about mass and weight?
(a) Mass and weight are the same quantity
(b) Mass changes from place to place, but weight does not
(c) Mass is constant, but weight changes with gravity
(d) Both mass and weight change with temperature
Answer:
(c) Mass is constant, but weight changes with gravity
Question 10.
The reason a stone sinks in water but a plastic ball floats is (Competency Based Que.)
(a) stone is heavier
(b) plastic ball is larger
(c) stone has greater density than water
(d) stone is smooth
Answer:
(c) stone has greater density than water
Question 11.
An object will float in water if
(a) its weight is more than upthrust
(b) its density is more than water
(c) its weight is equal to upthrust
(d) there is no gravity
Answer:
(c) its weight is equal to upthrust
Question 12.
Which of the following is true for an object that sinks in water?
(a) Buoyant force is greater than the weight
(b) Buoyant force equals weight
(c) Weight is greater than buoyant force
(d) There is no force acting
Answer:
(c) Weight is greater than buoyant force
Question 13.
Which of the following statements about force is not correct?
(a) Force can change the shape of an object
(b) Force can change the direction of motion
(c) Force always results in motion
(d) Force can stop a moving object
Answer:
(c) Force always results in motion
Question 14.
A book is kept on a table. The table exerts an upward force on the book even though it appears to be doing nothing. What kind of force is this?
(a) Gravitational force
(b) Applied force
(c) Normal reaction force
(d) Frictional force
Answer:
(c) Normal reaction force
Question 15.
While walking, we push the ground backward. Yet, we move forward. Which force is responsible for this?
(a) Frictional force
(b) Gravitational force
(c) Normal reaction
(d) Muscular force
Answer:
(a) Frictional force
Question 16.
A wooden block is floating on water. A metal cube is placed on it and the block sinks slightly. What force increases due to the added weight?
(a) Upthrust
(b) Gravitational force
(c) Magnetic force
(d) Electrostatic force
Answer:
(a) Upthrust
Question 17.
Why does a balloon filled with helium rise in the air while a rubber ball does not?
(a) Helium is lighter than air
(b) Rubber is heavier than air
(c) Upthrust is more oh helium
(d) Both (a) and (c)
Answer:
(d) Both (a) and (c)
Exploring Forces Class 8 Assertion Reason Questions
The following questions consist of two statements. Assertion (A) and Reason (R). Answer the following questions by selecting the appropriate option given below
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Question 1.
Assertion (A) A rubber ball changes shape when pressed.
Reason (R) Force can change the shape of soft object.
Answer:
(a) A force can deform soft object like rubber. The reason explains the assertion correctly.
Question 2.
Assertion (A) Friction slows down a moving object.
Reason (R) Friction always acts in the direction of motion.
Answer:
(c) Friction slows objects by opposing motion, not by acting in the same direction.
Question 3.
Assertion (A) Firction is not useful while walking.
Reason (R) Friction reduces our ability to move.
Answer:
(d) Friction helps us walk. Without it, we would slip.
Question 4.
Assertion (A) An object experiences upthrust when immersed in water.
Reason (R) Liquids apply upwards force submerged objects.
Answer:
(a) Both are correct, when an object is in a liquid, the liquid exerts an upward froce called buoyant force (upthrust).
Question 5.
Assertion (A) A person floats easily in salty water than in pure water.
Reason (R) Salt water has greater density and provides more upthrust.
Answer:
(a) Salt water is denser, so it provides more buoyant force, making it easier to float.
Question 6.
Assertion (A) When a deflated football is pressed, it gets deformed.
Reason (R) The applied force changes the shape of the object.
Answer:
(a) Both A and R are true and R is the correct explanation of A.
Question 7.
Assertion (A) When we stop pedaling a bicycle, it gradually comes to rest.
Reason (R) In the absence of a force, objects remains at rest.
Answer:
(b) Both A and R are true but R is not the correct explanation of A.
Question 8.
Assertion (A) Iron filings get arranged in a pattern around a magnet.
Reason (R) Magnetic field lines are invisible and have a definite direction.
Answer:
(a) Both A and R are true and R is the correct explanation of A.
Question 9.
Assertion (A) A plastic scale when rubbed on dry hair attracts tiny paper bits.
Reason (R) Rubbing generates magnetic properties in plastic.
Answer:
(c) A is true but R is false.
Question 10.
Assertion (A) An iron nail sinks in water, but a ship made of iron floats.
Reason (R) The shape and design of the ship reduce its overall density.
Answer:
(a) Both A and R are true and R is the correct explanation of A.
Exploring Forces Class 8 Case Based MCQ Questions
Question 1.
Ravi was helping his father move a wooden cart full of vegetables along a cemented road. He noticed that pushing the cart required considerable effort. Once he stopped pushing, the cart gradually slowed down and came to a halt. His father explained that the surface of the road was rough and this affected the movement of the cart. (Competency Based Que.)
(i) What type of force does Ravi use to push ther cart?
(a) Gravitational force
(b) Muscular force
(c) Magnetic force
(d) Electrostatic force
Answer:
(b) Muscular force
(ii) Why does the cart stop moving after Ravi stops pushing it?
(a) Lack of air pressure
(b) Magnetic pull
(c) Friction between the cart wheels and road
(d) Gravitational repulsion
Answer:
(c) Friction between the cart wheels and road
(iii) What would happen if the road were completely smooth?
(a) The cart would move faster
(b) The cart would fly
(c) Friction would increase
(d) Cart would stop immediately
Answer:
(a) The cart would move faster
Question 2.
Priya read in her science book that an object weighing 60 newtons on Earth would weigh only about 10 newtons on the Moon. She was confused because she thought the object remained the same. Her teacher explained that while the object’s mass stays constant, the weight changes depending on the gravitational force of the planet or moon. (Competency Based Que.)
(i) What causes the weight of an object to change on the Moon?
(a) Air pressure
(b) Gravitational force
(c) Mass
(d) Shape of the object
Answer:
(b) Gravitational force
(ii) Which of the following remains constant everywhere?
(a) Weight
(b) Volume
(c) Mass
(d) Gravitational pull
Answer:
(c) Mass
(iii) Which instrument is used to measure weight?
(a) Ruler
(b) Thermometer
(c) Spring balance
(d) Measuring cylinder
Answer:
(a) Ruler
Exploring Forces Class 8 Fill in the blanks
1. When two forces acting on an object are equal in size and opposite in direction, they are called ………………………… forces.
Answer:
Balanced
2. Force applied by muscles of humans or animals is known as ……………………. force.
Answer:
Muscular
3. When an object moves with increasing speed, a force must be acting in the ………………………. direction as its motion.
Answer:
Same
4. On a smooth surface, a rolling ball continues to move longer because the force of ………………………….. is less.
Answer:
Friction
5. Like poles of a magnet ………………………… each other, while unlike poles ……………….. each other.
Answer:
Repel, attract
6. The reading on a weighing machine would be less on the Moon than on Earth because the value of ………………………… is less there.
Answer:
Gravity
7. Although two bags look the same in size, one feels heavier because it has more ………………………… inside it.
Answer:
Mass
8. While swimming, our body feels lighter in water because water exerts an upward force called ………………………… on us.
Answer:
Upthrust
9. A ship made of iron floats in water because its overall density is less than water due to the large volume of ………………………… inside it.
Answer:
Air
10. If upthrust on an object is less than its weight, the object will …………………………
Answer:
Sink
11. A moving object comes to rest due to the opposing force of ……………………. between its surface and the surface it moves on.
Answer:
Friction
12. When you separate your clothes after drying, a crackling sound may be heard due to the build-up of ……………………….. .
force.
Answer:
Electrostatic
13. A magnetic force is an example of a ……………………… force, as it can act without touching the object.
Answer:
Non-contact
14. The reason why all objects fall towards the Earth when dropped from a height is the ……………………….. force acting between the object and the Earth.
Answer:
Gravitational
15. If a plastic ball floats on water but sinks in alcohol, it means that the ………………………….. of alcohol is less than that the ball.
Answer:
Density
Exploring Forces Class 8 True or False
1. Force is needed only to start motion, not to change direction.
Answer:
False
2. Balanced forces can change the shape of an object.
Answer:
True
3. Muscular force can act at a distance.
Answer:
False
4. Friction is a non-contact force.
Answer:
False
5. A balloon rubbed on hair can attract small bits of paper.
Answer:
True
6. Gravitational force only acts on objects that are in motion.
Answer:
False
7. The Moon has no gravity, so objects become weightless there.
Answer:
False
8. Electrostatic force can act from a distance.
Answer:
True
9. A wooden block sinks in water because it is solid.
Answer:
False
10. Buoyant force increases as the object is pushed deeper into the fluid.
Answer:
True
11. A moving object always comes to rest on its own due to friction.
Answer:
True
12. Electrostatic force can both attract and repel.
Answer:
True
13. Magnetic force requires contact between the magnet and the object.
Answer:
False
14. Gravitational force acts only on objects that are on Earth.
Answer:
False
15. Buoyant force is greater in water than in air.
Answer:
True
Exploring Forces Class 8 Match the following
Question 1.
Match the Column I with Column II.
| Column I | Column II |
| A. Gravitational force | 1. Iron nail near a magnet |
| B. Buoyant force | 2. Stone falling from a height |
| C. Magnetic force | 3. Floating cork in water |
| D. Contact force | 4. Pushing a table |
Answer:
A – 2, B – 3, C – 1, D – 4
| Column I | Column II |
| A. Gravitational force | 2. Stone falling from a height |
| B. Buoyant force | 3. Floating cork in water |
| C. Magnetic force | 1. Iron nail near a magnet |
| D. Contact force | 4. Pushing a table |
Question 2.
Match the Column I with Column II.
| Column I | Column II |
| A. Rubbing hand together | 1. Electrostatic force together |
| B. Balloon attracting paper | 2. Frictional force paper |
| C. Object falling freely | 3. Gravitational force |
| D. Iron piece pulled by magnet | 4. Mangnetic force magnet |
Answer:
A – 2, B – 1, C – 3, D – 4
| Column I | Column II |
| A. Rubbing hand together | 2. Frictional force paper |
| B. Balloon attracting paper | 1. Electrostatic force together |
| C. Object falling freely | 3. Gravitational force |
| D. Iron piece pulled by magnet | 4. Mangnetic force magnet |