Tag: physics

Questions Related to physics

When we hear a sound, we can identify it source from

physics world of sounds sound produced by humans propagation of sound production and propagation of sound

  1. The frequency of the sound

  2. The amplitude of the sound

  3. The wavelength of the sound

  4. The overtones present in the sound

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Correct Option: A
Explanation:

Frequency of the sound is the characteristic of sound waves that helps us to distinguish between two different sounds. For example, sound produced by man generally have low frequency (i.e. low pitch) whereas that produced by woman have higher frequency (i.e. sharp tone). Thus we can distinguish between two sounds by hearing the frequency (pitch).

When a body is at rest, it is obeying :

physics kinematics motion around us motion and rest moving things around us

  1. Principle of conservation of energy

  2. Newton's first law

  3. Ohm's law

  4. Newton's second law

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Correct Option: B
Explanation:

Newton's first law states that; "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force".Thus, body continues in it's state of rest as there is no external force on it,

So, option B is correct.

If a body does not change its position with respect to its surroundings, the body is said to be at rest.

physics kinematics motion around us motion and rest moving things around us

  1. True

  2. False

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Correct Option: A
Explanation:

The body when considered in frame of reference of surroundings, then zero relative velocity means it is at rest. So. statement is true.

In which of the following cases , the net force is zero?
I) A ball freely falling from a certain height
II) A cork floating on the surface of water
III) An object floating in air

physics kinematics motion around us motion and rest moving things around us

  1. I and II only

  2. II and III only

  3. III and I only

  4. I, II and III

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Correct Option: B

In the state of equilibrium
I) Net force is zero
II) Body at rest will continue to be in its state of rest
III) Body moving with uniform velocity will continue to be in its state of uniform velocity
IV) Body with linear momentum $\vec{p}$ will continue to have the same momentum $\vec{p}$.

physics kinematics motion around us motion and rest moving things around us

  1. all are correct

  2. I, II, III are correct

  3. II, III, IV are correct

  4. None of these

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Correct Option: A

At the starts of a motion along a line the initial velocity is u and acceleration is at. The final velocity v is 

physics kinematics motion around us motion and rest moving things around us

  1. v=u+at

  2. v=u+$at^{2}$

  3. $v=u+\frac{1}{2}at^{2}$

  4. v=$at^{2}$

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Correct Option: A
Explanation:

Let us assume a body that has a mass “m” and initial velocity “u”. Let after time “t” its final velocity becomes “v” due to uniform acceleration “a”. Now we know that:

Acceleration = Change in velocity/Time Taken

Therefore,  Acceleration = (Final Velocity-Initial Velocity) / Time Taken

Hence, a = v-u /t or at = v-u

Therefore, we have: v = u + at

The pendulum of a wall clock exhibits

physics kinematics motion around us motion and rest moving things around us

  1. Rotatory motion

  2. Circular motion

  3. Linear motion

  4. Oscillatory motion

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Correct Option: A

Symmetry of the laws of nature with respect to translation in time give rise to

physics kinematics motion around us motion and rest moving things around us

  1. Conservation of linear momentum

  2. Conservation of angular momentum

  3. Conservation of cahrge

  4. Conservation of energy

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Correct Option: A
Explanation:

Time translation symmetry gives rise to the conservation of energy.

Space translation symmetry gives rise to conservation of momentum.

Rotational symmetry gives rise to conservation of angular momentum.

The conservation law associated with this symmetry is the conservation of electrical charge.

 

White colour of the cloud is due to ___________________.

physics physical world introduction to science contribution of physics in technology and society physics in relation to other sciences

  1. reflection of seven colors of light

  2. refraction of seven colors of light

  3. scattering of seven colors of light

  4. absorption of seven colors of light

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Correct Option: C
Explanation:

Large dust particles and water droplets scatter all wavelength almost equally. Hence clouds appears white.

A person walks $100$m, holding a suitcase of weight $100$N. The work done by the applied force is _________J.

physics physical world introduction to science contribution of physics in technology and society physics in relation to other sciences

  1. $10000$

  2. $100$

  3. $Zero$

  4. $5000$

Show answer
Correct Option: C
Explanation:

To holding the weight force will act vertically, 

Displacement of the bock is horizontal 
Work done $= F \cdot a = F a cos \theta=0 $