Updated by Tiwari Academy
on June 12, 2023, 8:34 AM
Class 8 Science Chapter 8 MCQ (Multiple Choice Questions) of Force and Pressure for CBSE and State boards like UP board, MP board and other board who are following NCERT books for session 2023-24. All the questions are taken from latest NCERT books issued for new academic session. Practice with these questions to clear all of your doubts and to be confident in exams. Class 8 science chapter 8 MCQs covers the entire chapter and all the topics with suitable answers and explanation.
Class 8 Science Chapter 8 MCQ
Class: 8
Science
Chapter: 8
Force and Pressure
Contents:
MCQ Online Test with answers
Session:
2023-24
MCQ Tests with Answers for Class 8 Science Chapter 8
Q1
Which of the following is not an example of muscular force?
[A]. A porter carrying a load on a wheel-barrow.
[B]. An apple falling from a tree.
[C]. A child riding a bicycle.
[D]. A person drawing water from a well.
Answer: Option B
Explanation:
All are the examples of muscular force except one. An apple falling from a tree is example of gravitational force. The force with which the earth pulls the objects towards it, is called the force of gravity. Gravity is a natural force of attraction or pull.
Two boys A (left side) and B (right side) are applying force on a block. If the block moves towards the right, which one of the following statements is correct?
[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: Option A
Explanation:
Magnitude of force applied by A is greater than that of B because the block moves towards right i.e., towards B.
When we press the bulb of a dropper with its nozzle kept in water air in the dropper is seen to escape in the form of bubbles. Once we release the pressure on the bulb, water gets filled in the dropper. The rise of water in the dropper is due to:
[A]. Pressure of water
[B]. Gravity of the earth
[C]. Shape of rubber bulb
[D]. Atmospheric pressure
Answer: Option D
Explanation:
A dropper works on the existence of atmospheric pressure. When we press the rubber bulb of the dropper by keeping its nozzle dipped in water or liquid, the air present in the glass tube and bulb is seen to escape in the form of bubbles. Due to this, the air pressure inside the glass tube and rubber bulb of dropper is very much reduced. When we now released the rubber bulb of dropper, the much greater atmospheric pressure acting on the surface of liquid, pushes the liquid up into the dropper tube.
A rectangular wooden block has length, breadth and height of 50 cm, 25 cm and10 cm, respectively. This wooden block is kept on ground in three different ways, turn by turn. Which of the following is the correct statement about the pressure exerted by this block on the ground?
[A]. The maximum pressure is exerted when the length and breadth form the base
[B]. The maximum pressure is exerted when length and height form the base
[C]. The maximum pressure is exerted when breadth and height form the base
[D]. The minimum pressure is exerted when length and height form the base
Answer: Option C
Explanation:
As we know that pressure exerted by the body is inversely proportional to the area where force is applied. So, which has less area of cross section in contact with the surface will exert more pressure on the ground. It is clear that height from the base exerts more pressure. Therefore, the maximum pressure is exerted when length and height form the base.
Which of the following are contact forces?
[A] Friction and Gravitational force
[B] Gravitational force and Magnetic force
[C] Friction and Muscular force
[D] Gravitational force and Muscular force
If we release a magnet held in our hand, it falls to the ground. The force responsible for this is:
[A]. Muscular force
[B]. Magnetic force
[C]. Electrostatic force
[D]. Gravitational force
Answer: Option D
Explanation:
The force with which the earth pulls the objects towards it, is called the force of gravity. Gravity is a natural force of attraction or pull.
If we drop a stone from some height, it falls down towards the earth. A leaf falls from the tree due to gravity. Rain falls down to earth due to the force of gravity. When we open a tap, water begins to flow down towards the ground due to the force of gravity. There are so many examples of gravitational force.
Which of the following force is utilized in reducing air pollution by removing dust, soot and fly-ash particles from the smoke coming out of chimneys of factories?
[A]. Magnetic force
[B]. Gravitational force
[C]. Electrostatic force
[D]. Frictional force
Answer: Option D
Explanation:
An electrostatic precipitator is a type of filter (dry scrubber) that uses static electricity to remove soot and ash from exhaust fumes before they exit the smokestacks. This one common air pollution control device. Most power stations burn fossil fuels such as coal or oil to generate electricity for use.
Which of the following does not work on the existence of atmospheric pressure?
[A]. Rise of iodine solution in the glass tube of dropper
[B]. Rise of cold drink in a long plastic straw
[C]. Sticking of suction hook on the wall of a room
[D]. Rise of mercury in glass tube of thermometer
Answer: Option D
Explanation:
The rise in the level of mercury in glass tube of thermometer will not work due to the presence of atmospheric pressure. A thermometer works on the principle that mercury expands with increase in temperature. So, the mercury in a glass tube of thermometer will rise only due to increase in temperature.
Payal is completed her science chapter where she wrote some statements. She wants to know whether the statements are correct or not? Payel wants to take help from you:
[A]. Pressure is produced when a force acts on an object.
[B]. The force with which the earth pulls the objects towards it, is called the force of gravity.
[C]. The gravitational force between the sun and the earth which holds the earth in its orbit around the sun.
[D]. None of the above.
Answer: Option D
Explanation:
Here, all the statements are correct. Hence, your answer will be option [D].
Which of the following is not a non-contact force?
[A]. Electrostatic force
[B]. Gravitational force
[C]. Frictional force
[D]. Magnetic force
Answer: Option C
Explanation:
A force which can be exerted by an object on another object only through “physical touching” is called a contact force. Such as:
i)Muscular force and
ii)Friction force
These are example of contact forces, but a force which can be exerted by an object on another object even from a distance (without touching) is called a non-contact force. Such as,
i)Magnetic force
ii)Electrostatic force and
iii)Gravitational force
The force of 150 N is applied to an object of area 3 m2. Calculate the pressure.
[A]. 25 N/m2
[B]. 50 N/m2
[C]. 100 N/m2
[D]. 147 N/m2
Answer: Option B
Explanation:
Force = 100 N, Area = 3 m2
Putting these values in the formula for pressure:
Pressure = 100 N/2 m2
= 50 N/m2
Thus, the pressure is 50 newtons per square meter or 50 pascals.
Which of the following scientists gave the idea of the existence of gravitational force?
[A]. Einstein
[B]. James Watt
[C]. Faraday
[D]. Newton
Answer: Option D
Explanation:
The English scientist Isaac Newton had given the idea for gravitational force when he saw an apple fall from a tree. The force with which the earth pulls the objects towards it, is called the force of gravity. Gravity is a natural force of attraction. We are all pulled (including every object) to the earth by the force of gravity.
A blunt knife does not cut an object easily because:
[A]. Thicker edge produces lesser pressure.
[B]. The thicker edge does not transfer the force.
[C]. It can be used to cut the butter
[D]. The weight of knife controlled by object
Answer: Option A
Explanation:
A blunt knife does not cut an object easily because due to its thicker edge, the force of our hand falls over a larger area of the object and produces lesser pressure. This lesser pressure cuts the object with difficulty.
The magnitude of atmospheric pressure is equal to the pressure exerted by a:
[A]. 76 mm tall column of mercury
[B]. 760 mm tall column of alcohol
[C]. 76 cm tall column of mercury
[D]. 760 cm tall column of mercury
Answer: Option C
Explanation:
We know that the SI unit of pressure is pascal (Pa) but atmospheric pressure is usually measured in the unit of “millimeter of mercury” (mm of mercury) for the sake of convenience in measuring it. The atmospheric pressure on the surface of earth (at the sea level) is 760 mm of mercury.
The atmospheric pressure is usually measured in the unit of:
[A]. Newtons per square meter
[B]. Pascal
[C]. Cm of mercury
[D]. Mm of mercury
Answer: Option D
Explanation:
The SI unit of pressure is pascal (Pa) but atmospheric pressure is usually measured in the unit of “millimeter of mercury” (mm of mercury) for the sake of convenience in measuring it.
In the last year board examination, Rahul were asked a question where he had to choose the statement which was/were correct? Will you be able to answer this question?
[A]. The drinking straw works on the existence of atmospheric pressure.
[B]. The syringe works on the existence of atmospheric pressure.
[C]. A dropper works on the existence of atmospheric pressure.
[D]. All the above
Answer: Option D
Explanation:
Here, all the statements are correct. Hence, your answer will be option [D].
When a force of 5 N acts on a surface, it produces a pressure of 500 Pa. The area of surface then must be
[A]. 10 cm2
[B]. 50 cm2
[C]. 100 cm2
[D]. 0.01 cm 2
Answer: Option C
Explanation:
The pressure depends on two factors: a) Force applied and b) Area over which force acts.
Pressure = Force / Area
Area = Pressure / Force
= 500/ 5
= 100 cm2
Just read the complete chapter from NCERT Textbook and go through the exercise questions answers given at the end of the chapter of NCERT book. Now work on important questions and MCQ questions to learn thoroughly the entire chapter 8 of class 8 Science.