Tag: physics

Questions Related to physics

A simple pendulum of length L and having a bob of mass m is suspended in a car. The car is moving on a circular track of radius R with a uniform speed v. If the pendulum makes small oscillations in a radial direction about its equilibrium positions, its time period of oscillation is:

angular simple harmonic motion example of simple harmonic motion oscillatory motion oscillations physics

  1. $ T = 2 \pi \sqrt{\dfrac{L}{g}}$

  2. $T = 2 \pi \sqrt{\dfrac{L}{\sqrt{g^2}+ \dfrac{v^4}{R^2}}}$

  3. $T = 2 \pi \sqrt{\dfrac{L}{\sqrt{g^2}+ \dfrac{v^2}{R}}}$

  4. $T = 2 \pi \sqrt{\dfrac{L}{\sqrt{g^2}- \dfrac{v^4}{R^2}}}$

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Correct Option: B
Explanation:

The period of the pendulum, $T=2\pi \sqrt{\cfrac{L}{a}}$ where $a=$ $\text{resultant acceleration}\=\sqrt{g^2+{(\cfrac{V^2}{R})}^2}\quad\quad\quad\quad [\cfrac{V^2}{R}=\text{centripital acceleratiop }, g=\text{acceleration due to gravity}]$.

$\therefore T=2\pi\sqrt{\cfrac{L}{g^2+\cfrac{V^4}{R^2}}}$
Option B is the correct answer.


Fill in the blank.

Pressure affects ________ substances.

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. solid

  2. liquid

  3. gaseous

  4. solid, liquid and gaseous

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Correct Option: D
Explanation:

Pressure affects substances in al the state whether it is liquid, solid or gaseous.

Pressure = ?

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. force $\times$ area

  2. force / area

  3. mass / area

  4. area / force

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Correct Option: B
Explanation:

Pressure is the force acting on a unit area of a surface it can be written as pressure  $= \dfrac{force}{area}$

Fill in the blank.

The force acting on a unit area of a surface is called____.

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. atmospheric pressure

  2. pressure

  3. muscular force

  4. none of these

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Correct Option: B
Explanation:

Pressure is force acting on a unit area of a surface when force applied on object in a particular area of object exert pressure on it.

A force is called thrust when it acts

physics statics and dynamics of fluid (liquid and gas) pressure in liquids and gases pressure dependence on force and area concept of pressure

  1. normal to the surface

  2. inclined to the surface

  3. parallel to the surface

  4. at any arbitrary direction on the surface

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Correct Option: A
Explanation:

When a force acts vertically downwards or normal to the surface under consideration, it is called thrust.

Which of the following statements is correct?

physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

  1. Sound travels as waves

  2. Sound travels in straight lines

  3. Sound is a form of energy

  4. All of these

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Correct Option: A
Explanation:

Sound travels as mechanical waves. A mechanical wave is a disturbance that moves and transports energy from one place to another through a medium. In sound, the disturbance is a vibrating object. And the medium can be any series of interconnected and interactive particles. This means that sound can travel through gases, liquids and solids.

Solution A: Sound travels as waves.

Sound waves in air cannot be polarised because they are 

physics world of sounds time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

  1. progressive

  2. stationary

  3. transverse

  4. longitudinal

Show answer
Correct Option: D
Explanation:

It is a conceptual and memory based question.

A pure sine wave is called 

physics world of sounds time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

  1. chord.

  2. melody

  3. tone

  4. overtone

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Correct Option: C
Explanation:

A pure sine wave with a certain frequency is called tone.
option "C" is correct.

A supersonic jet produces waves in air. The wave front is

physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

  1. ellipsoidal

  2. conical

  3. spherical

  4. paraboloidal

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Correct Option: B
Explanation:

These waves are also called as shock waves, which are of conical shape when, a supersonic air craft moves faster than sound.

Which factors determine the quality of the note ?

physics world of sounds time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

  1. Wavelength.

  2. Frequency

  3. Time period.

  4. Wave form.

Show answer
Correct Option: D
Explanation:

Quality is used to describe the quality of the waveform as it appears to the listener. Therefore,  the quality of a note depends upon the waveform. 
Two notes of the same pitch and loudness, played from different instruments do not sound the same because the waveforms are different and therefore differ in quality or tone.