Tag: physics

Questions Related to physics

Resonance is exhibited in 

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. quartz crystals

  2. clocks

  3. ear membranes

  4. pendulum

Show answer
Correct Option: A,B,C,D
Explanation:

$Answer:-$ A,B,C,D

Various examples of mechanical resonance include:

  • Most clocks keep time by mechanical resonance in a balance wheel,pendulum, or quartz crystal.
  • Orbital resonance as in some moons of the solar system's gas giants.
  • The resonance of the basilar membrane in the ear.
  • Making a child's swing swing higher by pushing it at each swing.
  • A wineglass breaking when someone sings a loud note at exactly the right pitch.

What conditions are necessary to produce resonance in an object?

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. The object must have at least one natural frequency of vibration.

  2. The object must be driven by an external vibrating force.

  3. The frequency of the external vibrating force must match the object's natural frequency of vibration.

  4. All of the above.

Show answer
Correct Option: D
Explanation:

Resonance is a phenomenon in which the periodic oscillatory force acting on an object has a frequency of vibration same as the natural frequency of the object. In this, the object vibrates with a large amplitude.

Pick the wrong statement:

Interference to occur:

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. frequency of one wave should be equal to another

  2. amplitude of one wave should be comparable to that of another

  3. one wave must superpose on another

  4. frequency of two waves can never be same / equal

Show answer
Correct Option: D
Explanation:

Interference is a phenomenon in which two waves of equal frequencies and nearly equal amplitudes superpose on one another and produce a resultant new wave.

If a singer could match the natural frequency of the wine glass, he:

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. can shatter the glass

  2. can still never shatter the glass

  3. can at most vibrate the glass

  4. can leave no effect on the glass

Show answer
Correct Option: A
Explanation:

$Answer:-$ A 

If a singer could match the natural frequency of the wine glass than he could possibly shatter the glass as coming into resonance would make every atomic particle of glass to vibrate and thereby increasing distance between two particles and hence can actually break.

State whether the given statement is True or False :

Resonance is the cause of sound production in musical instruments.

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Resonance is cause of sound production in musical in instrument. this statement is true. Generally musical instrument have a hollow chamber, it contains air particle. when vibration is produced, it may be in the objects attached to it, the frequency of this object may match with a natural frequency of air particle inside the hollow chamber. Thus the air particles start to vibrate with the large amplitude which produces large sound. 

Resonance occurs when a vibrating system or external force drives another system to ____ with greater _ at a specific preferential ______. Fill in the blanks. 

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. oscillate, amplitude, frequency

  2. oscillate, frequency, amplitude

  3. vibrate, velocity, frequency

  4. vibrate, frequency, velocity

Show answer
Correct Option: A
Explanation:

$Answer:-$ A

In physics, resonance is a phenomenon that occurs when a given system is driven by another vibrating system or external force to oscillate with greater amplitude at a specific preferential frequency.

Resonance occurs when a system is able to store and easily transfer energy between two or more different storage modes (such as kinetic energy and potential energy in the case of a pendulum). However, there are some losses from cycle to cycle, called damping. When damping is small, the resonant frequency is approximately equal to the natural frequencyof the system, which is a frequency of unforced vibrations. Some systems have multiple, distinct, resonant frequencies.
Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, acoustic resonance, electromagnetic resonance, nuclear magnetic resonance(NMR), electron spin resonance (ESR) and resonance of quantum wave functions. Resonant systems can be used to generate vibrations of a specific frequency (e.g., musical instruments), or pick out specific frequencies from a complex vibration containing many frequencies (e.g., filters).

In a resonance tube with tuning fork of frequency $512 \ Hz$, first resonance occurs at water level equal to $30.3 \ cm$ and second resonance occurs at $63.7 \ cm$. The maximum possible error in the speed of sound is

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. $51.2 \ cm/s$

  2. $102.4 \ cm/s$

  3. $204.8 \ cm/s$

  4. $153.6 \ cm/s$

Show answer
Correct Option: C
Explanation:

$\begin{array}{l} { l _{ 1 } }+e=\frac { V }{ { 4f } } \to \left( i \right)  \ { l _{ 2 } }+e=\frac { { 3V } }{ { 4f } } \to \left( { ii } \right)  \ Sub\, \, \left( { ii } \right) \, \, & \, \, \left( i \right)  \ { l _{ 2 } }-{ l _{ 1 } }=\frac { { 2V } }{ { 4f } }  \ { l _{ 2 } }-{ l _{ 1 } }=\frac { V }{ { 2f } }  \ \frac { { \Delta \left( { { l _{ 2 } }-{ l _{ 1 } } } \right)  } }{ { { l _{ 2 } }-{ l _{ 1 } } } } =\frac { { \Delta V } }{ V }  \ \Delta V=2f\Delta \left( { { l _{ 2 } }-{ l _{ 1 } } } \right) =2f\left( { \Delta { l _{ 1 } }+\Delta { l _{ 2 } } } \right) ......for\, \, man\, \, error \ =2\times 512\times \left( { 0.1+0.1 } \right) =204.8\, \, cm/s \end{array}$

The phenomenon of resonance is used in receiving the radio and television programmes.

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. True

  2. False

  3. Nither

  4. Either

Show answer
Correct Option: A
Explanation:

This is a resonance in the circuit--- when you have a bunch of different

frequencies driving a resonant system, the response is only strong for

those frequencies which are close to the natural frequency of the

resonant oscillator. The frequency dependent amplification  is used to done through the resonance circuit for a desired frequency.

In a resonance column experiment the first resonance is obtained when the level of the water in tube is $20$cm from the open end. Resonance will also be obtained when the water level is at a distance of :

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. $40$ cm from the open end

  2. $60$ cm from the open end

  3. $80$ cm from the open end

  4. $100$ cm from the open end

Show answer
Correct Option: B,D
Explanation:
For $1^{st}$ resonance $(1/4)\lambda =L$
$\Rightarrow \lambda =4L$ ..(i)
For $2$nd resonance
$3\left(\dfrac{\lambda}{4}\right)=L _2\Rightarrow \lambda =\dfrac{4L _2}{3}$ .(ii)
By using (i) and (ii)
$\dfrac{4L _2}{3}=4L _1$
$\Rightarrow L _2=3L _1=3(20)=60$cm
Similarly, $L _3=5L _1=100$ cm
Hence (B) and (D) are correct.

The third overtone of a pipe is found to be in unison with the first overtone of an open pipe. The ratio of lengths of the pipes is 

physics free, damped and forced oscillations resonance: examples and uses resonance oscillatory motion

  1. $\dfrac { 3 }{ 4 }$

  2. $\dfrac { 3 }{ 5 }$

  3. $\dfrac { 2 }{ 5 }$

  4. $\dfrac { 7 }{ 4 }$

Show answer
Correct Option: D