MCQ
A sinusoidal progressive wave is generated in a string. It’s equation is given by $y = (2\,\, mm) sin (2\pi x - 100 \pi t + \pi /3)$. The time when particle at $x = 4$ $m$ first passes through mean position, will be
  • A
    $\frac{1}{{150}}\, sec$
  • B
    $\frac{1}{{12}}\, sec$
  • $\frac{1}{{300}}\,sec$
  • D
    $\frac{1}{{100}}\,sec$ 

Answer

Correct option: C.
$\frac{1}{{300}}\,sec$
c
$y=2 m m \sin \left(2 \pi x-100 \pi t+\frac{\pi}{3}\right)$

$\Rightarrow 0=2 \sin \left(2 \pi x-100 \pi t+\frac{\pi}{3}\right)$

$\Rightarrow n \pi=8 \pi-100 \pi t+\frac{\pi}{3}(n=0,1,2,3 \dots)$

$\Rightarrow t_{\min }=\frac{\frac{25 \pi}{3}-n \pi}{100 \pi}=\frac{\pi}{3} / 100 \pi=\frac{1}{300} s$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Two waves of equal amplitude A and equal frequency travel in the same direction in a medium. The amplitude of the resultant wave is:
Two droplets merge with each other and forms a large droplet. In this process
A block of mass $m$ (initially at rest) is sliding up (in vertical direction) against a rough vertical wall with the help of a force $F$ whose magnitude is constant but direction is changing. $\theta  = {\theta _0}t$  where $t$ is time in sec. At $t$ = $0$ , the force is in vertical upward direction and then as time passes its direction is getting along normal, i.e., $\theta  = \frac{\pi }{2}$ .The value of $F$ so that the block comes to rest when $\theta  = \frac{\pi }{2}$ , is 
When red glass is heated in dark room it will seem
The equation of a wave is given as $y = 0.07\sin (12\pi x - 3000\pi t)$. Where $x$ is in metre and $t$ in sec, then the correct statement is
The weight of an aeroplane flying in air is balanced by
Light of wavelength $\lambda$ falls on a metal having work function $\frac{\text{h}_\text{c}}{\lambda_0}.$ Photoelectric effect will take place only if:

  1. $\lambda\geq\lambda_0$

  2. $\lambda\geq2\lambda_0$

  3. $\lambda\leq\lambda_0$

  4. $\lambda<\frac{\lambda_ 0}{2}.$

A billiard table whose length and width are as shown in the figure. $A$ ball is placed at point $A$. At what angle ‘$\theta $ ’the ball be projected so that after colliding with two walls, the ball will fall in the pocket $B$ .Assume that all collisions are perfectly elastic (neglect friction)
The earth is an approximate sphere. If the interior contained matter which is not of the same density everywhere, then on the surface of the earth, the acceleration due to gravity.
A $100$ $Newton$ weight is suspended in a corner of a room by two cords $A$ and $B$ as shown in the figure below. The tension in the horizontal cord $A$ is ............ $N$