Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

One sound wave strikes a person's ear every $1/100$ of a second. The speed of sound where the person is located is $345 m/s$.
What is the frequency of the sound?

  1. $3.45\ Hz$

  2. $34,500\ Hz$

  3. $0.01\ Hz$

  4. $100\ Hz$

  5. $2.9\ Hz$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Time period of sound wave       $T = \dfrac{1}{100}$ second


$\therefore$ Frequency of sound wave      $\nu = \dfrac{1}{T} =100$  $Hz$

Multiple choice physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

If you go on increasing the stretching force on a wire in a guitar, its frequency

  1. Increases

  2. Decreases

  3. Remains unchanged

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When a stretching force is applied to a string or a wire, it applies a restoring force in the opposite direction. This force tends to bring the wire in its original length. It is known as tension in wire.

When we apply a stretching force on the wire of a guitar, the wire applies tension backwards. Greater the stretching force, greater is the tension.
The frequency of vibration of a stretched wire is directly proportional to the square root of the tension in it.
Hence on increasing the stretching force on a wire in a guitar, its frequency increases

Multiple choice physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

The sounds having frequency of $20$ Hz to $20,000$ Hz are

  1. Ultrasound

  2. Infrasonics

  3. Hypersonics

  4. Audible Sounds
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the case of sound waves, having frequency in between $20$ Hz and $20,000$ Hz, called audible sound and  waves of frequency smaller than $20$ Hz are called infrasonic and waves having frequency greater then $20,000$ Hz, called Hypersonics sounds.

Multiple choice physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

The time taken by a particle in reaching from a trough to its next crest in a transverse wave is

  1. T/4

  2. T/2

  3. T

  4. 3T/4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A crest and a trough are separated by a distance of $\lambda/2$. A distance of $\lambda/2$ corresponds to a time difference of T/2

Multiple choice physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

The equation of motion of a particle is $x = a cos(\alpha t)^2$. The motion is

  1. periodic but not oscillatory

  2. periodic and oscillatory

  3. oscillatory but not periodic

  4. neither periodic nor oscillatory.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The motion is oscillatory but not periodic because the oscillations are followed from the maximum displacement (negative extreme) at t=0, the corresponding echo is equal to π/2