Questions Related to physics

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

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

  1. muscular force

  2. force of friction

  3. gravitational force

  4. all of the above

Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  1. contact

  2. muscular

  3. gravitational

  4. electrostatic

Reveal answer Fill a bubble to check yourself
C Correct answer
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.

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

Which of the following is not a contact force?

  1. Tension force

  2. Normal force

  3. Air resistance

  4. None

Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

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

  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.

Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

Which of the following is a non-contact force?

  1. Gravitational force

  2. Magnetic forces

  3. Electric force

  4. All

Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

  1. Earth and tree

  2. Earth and fruit

  3. Earth and branch

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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.

  1. True

  2. False

Reveal answer Fill a bubble to check yourself
B Correct answer
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. 

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

Which one of the following forces is a contact force?

  1. Force of gravity

  2. Force of friction

  3. Magnetic force

  4. Electrostatic force

Reveal answer Fill a bubble to check yourself
B Correct answer
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.

Multiple choice physics propagation of sound waves longitudinal vs transverse wave sound and light comparison of speed of sound with speed of light

The ratio of speed of ultrasonic wave and sound wave is:

  1. $=1$
  2. $>1$
  3. $<1$
  4. $>1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ultrasonic wave is  defined as “inaudible sound with high frequency for human” the frequency of which generally exceeds 20 kHz. These days, sound wave which is not intended to be heard is also called Ultrasonic wave .


Ultrasonic wave is also a type of sound wave so ratio of velocity is $=1$