Class 8 Science Chapter 11 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 2023-2024. 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 11 MCQs covers the entire chapter and all the topics with suitable answers and explanation.
Class 8 Science Chapter 11 MCQ for 2023-2024
Class: 8
Science
Chapter: 11
Force and Pressure
Contents:
MCQ Online Test with answers
MCQ Tests with Answers for Class 8 Science Chapter 11
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.
In the electric bell circuit, when the circuit is completed, the hammer strikes the gong. Which of the following force is responsible for the movement of hammer?
[A]. Gravitational force alone
[B]. Electrostatic force alone
[C]. Magnetic force alone
[D]. Frictional force alone
Answer: Option C
Explanation:
It will be magnetic force because as electric current flows through the coil, it behaves like electromagnet and magnetic force is created.
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.
Which one of the following forces is a contact force?
[A]. Force of gravity
[B]. Force of friction
[C]. Magnetic force
[D]. Electrostatic force
Answer: Option B
Explanation:
Force of friction is a contact force. It always acts when the bodies are in contact. 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
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.
The same force “F” acts on four different objects having the areas given below, one by one. In which case the pressure exerted will be the maximum?
[A]. 20 m2
[B]. 50 m2
[C]. 10 m2
[D]. 100 m2
Answer: Option C
Explanation:
The force “F” is all the same in all situation making it constant. Using the formula: Pressure=Force/area.
This suggest that since “F” is constant, decrease in area will lead to increase in pressure and vice vasa. This may be represented by a real-life example with a sharp healed shoe of a lady and a normal shoe. If a lady weighing 140N may step on you while wearing the sharp healed shoe, the pain will be more severe than while wearing a normal flat shoe. Therefore, the lesser the area, the greater the pressure. Hence, your answer will be 10 m2, option [C].
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.
Which of the following change appreciably when a batsman hits a moving cricket ball?
[A]. Shape and Direction
[B]. Direction and Size
[C]. Shape and Size
[D]. Direction and Speed
Answer: Option D
Explanation:
A force can change the speed of a moving object. A force can change the direction of a moving object. A force can change the composition of a moving object. A force can change the shape and size of an object. But when a batsman hits a moving cricket ball, its direction and speed changed, not shape and size. Hence, your answer will be option [D].
[A]. A force can change the speed of a moving object
[B]. A force can change the direction of a moving object
[C]. A force can change the composition of a moving object
[D]. A force can change the shape and size of an object
Answer: Option C
Explanation:
A force can change the speed of a moving object. A force can change the direction of a moving object. A force can change the composition of a moving object. A force can change the shape and size of an object. But force cannot change the composition of a moving object or any object. Though composition is a chemical change.
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.
A school bag has wide strap made of thick cloth so that:
[A]. [A] The weight of bag creates less pressure.
[B]. The weight of bag easily transfers the shoulder.
[C]. The shape of bag can hold more books.
[D]. The weight of bag controlled by air pressure and blood pressure.
Answer: Option A
Explanation:
A school bag or shoulder bag has wide strap made of thick cloth (canvas) so that the weight of bag may fall over a large area of the shoulder of the child producing less pressure on the shoulder. And due to less pressure, it is more comfortable to carry the heavy school bag.
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.
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 11 of class 8 Science.