Tag: contact and non-contact forces

Questions Related to contact and non-contact forces

Attraction and repulsion between charged objects are examples of _______ force.

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. non-contact

  2. contact

  3. either contact or non-contact

  4. neither contact nor non-contact

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Correct Option: A
Explanation:

The attraction and repulsion between charged objects happen due to the action of electrostatic forces. Electrostatic force act between bodies not in contact. So, attraction and repulsion between charged objects are examples of non-contact force.

When you ride a cycle, force(s) acting on the cycle is/are

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. muscular force

  2. force of friction

  3. gravitational force

  4. all of the above

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Correct Option: D
Explanation:

To ride a cycle, you are to apply muscular force on the pedals of the cycle. The tyres of  the moving cycle are acted upon by the force of friction from the road. And, all objects on the earth are acted upon by the gravitational force.

Objects fall towards the earth because the earth pulls those. This pull is called _________ force.

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. contact

  2. muscular

  3. gravitational

  4. electrostatic

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Correct Option: C
Explanation:

Objects tend to fall downward towards the earth as the earth pulls the objects due to its gravity. The pull is known as gravitational force.

Electrostatic force is also a ____ force.

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. contact

  2. muscular

  3. non-contact

  4. gravitational

Show answer
Correct Option: C
Explanation:

In electrostatic force, force is exerted by an object on another object not in contact.

Which of the following is not a contact force?

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. Tension force

  2. Normal force

  3. Air resistance

  4. None

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Correct Option: D
Explanation:

Tension force, normal force and air resistance force act on the objects which are in physical contact (touch) with each other and thus all these forces are often called as contact forces.

Hence option D is correct.

Magnetic force is a non contact force because for magnetic force to apply

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. the bodies have to be in contact.

  2. the bodies need not be in contact.

  3. the bodies may or may not be in contact.

  4. none of these.

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Correct Option: B
Explanation:

Magnetic force, electric force and gravitational forces are non contact forces because for these forces to apply, the bodies need not be in contact (physically touch) with each other.

Which of the following is a non-contact force?

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. Gravitational force

  2. Magnetic forces

  3. Electric force

  4. All

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Correct Option: D
Explanation:

It is not necessary for the two objects to be in contact (touch) with each other to exert gravitation force, magnetic force and electric force. These three forces can be exerted even if the two objects are separated by a finite distance. Thus these forces are non-contact forces.

Fruits detached from a tree fall down due to force of gravity. We know that a force arises due to interaction between two objects. Name the objects interacting in this case.

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. Earth and tree

  2. Earth and fruit

  3. Earth and branch

  4. None of the above

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Correct Option: B
Explanation:

Earth and Fruits.
Here Force of gravity acts between the fruits and earth.
And due to this the fruit detached from the tree falls to the ground due to Force of gravity.

State whether true or false:

A boy throws a ball down from the second floor of a building. In this case, electrostatic force is acting on the ball.

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. True

  2. False

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Correct Option: B
Explanation:

When boy throws a ball down only gravitational force will act, as electrostatic force act between two charge particle , so there is only gravitational force that is acting on ball. 

Which one of the following forces is a contact force?

physics motion, force and speed contact and non-contact forces comparing force in magnetic, electric and gravitational fields identifying forces

  1. Force of gravity

  2. Force of friction

  3. Magnetic force

  4. Electrostatic force

Show answer
Correct Option: B
Explanation:

Friction is a surface phenomenon. When two surfaces have irregularities that come in contact do they get interlocked  preventing them against sliding against each other. So, frictional force is a contact force dependent on surface.
Here, option (B) is correct. 
Gravitational force, electrostatic force and magnetic force does not depend on the surface.