JEE PHYSICS MCQ: WAVES

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Application +4 | -1

100 \mathrm{~Hz}

sinusoidal wave is travelling in the positive

x

-direction along a string with a linear mass density of

3.5 \times 10^{-3} \mathrm{~kg} / \mathrm{m}

and a tension of

35 \mathrm{~N}

. At time

t=0

, the point

x=0

, has maximum displacement in the positive

y

-direction. Next when this point has zero displacement, the slope of the string is

\pi / 20

. Which of the following expression represent (s) the displacement of string as a function of

x

(in metre) and

t

(in second)

View answer and explanation

Correct option: A

y=0.025 \cos (200 \pi t-2 \pi x)

Option D (Will be one-fourth in number) is correct because the number of ejected electrons is proportional to the intensity of light, which decreases with the square of the distance.

More Questions from WAVES

Practice All Chapter MCQs →

The source of sound generating a frequency of

3\,\,kHz

reaches an observer with a speed of

0.5

times, the velocity of sound in air. The frequency heard by the observer is A source of sound emits waves with frequency

f\mathrm{ }Hz

and speed

V\mathrm{ }m/sec

. Two observers move away from this source in opposite directions each with a speed

0.2\,\,V

relative to the source. The ratio of frequencies heard by the two observers will be Assertion: The wave function of a pulse is given by

y = \frac{3}{{{{\left( {2x + 3t} \right)}^2} + 4}},

it propagates in

(– \mathrm{ve}) \,x

-direction.
Reason: The given wave function is of the form

y = f(kx +\omega t),

which represent a wave travelling in negative

X

-direction. In the fundamental mode, time taken by the wave to reach the closed end of the air filled pipe is

0.01\,\,s

. the fundamental frequency is A rope

5 \mathrm{~m}

long has a total mass of

245 \mathrm{~g}

. It is stretched with a constant tension of

1 \mathrm{~kg}

wt. If it is fixed at one end and shaken by hand at the other end, what frequency of shaking will make it break up into three vibrating segments? Take

g=980 \mathrm{~cm} \mathrm{~s}^{-2}

. If

T

is the reverberation time of an auditorium of volume

V

then