MCQ
A wave represented by the given equation $Y = A\sin \left( {10\,\pi \,x + 15\,\pi \,t + \frac{\pi }{3}} \right)$, where $x$ is in meter and $t$ is in second. The expression represents
  • A
    A wave travelling in the positive $X$ direction with a velocity of $1.5 \,m/sec$
  • B
    A wave travelling in the negative $X$ direction with a velocity of $1.5\, m/sec$
  • C
    A wave travelling in the negative $ X$ direction with a wavelength of $ 0.2\, m$
  • Both $(b)$ and $(c)$

Answer

Correct option: D.
Both $(b)$ and $(c)$
d
(d) Standard wave equation which travel in negative $x-$ direction is $y = A\sin (\omega \,t + kx + {\varphi _0})$

For the given wave $\omega = 2\pi n = 15\pi ,\,\,k = \frac{{2\pi }}{\lambda } = 10\pi $

Now $v = \frac{{{\rm{Co - efficient \,of\, }}t}}{{{\rm{Co - efficient \,of \,}}x}}$ $ = \frac{\omega }{k} = \frac{{15\pi }}{{10\pi }} = 1.5\,m/sec$

and $\lambda = \frac{{2\pi }}{k} = \frac{{2\pi }}{{10\pi }} = 0.2\,m.$

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

If a new planet is discovered rotating around Sun with the orbital radius double that of earth, then what will be its time period (in earth's days)
An $ L-$ shaped tube with a small orifice is held in a water stream as shown in fig. The upper end of the tube is $ 10.6 cm$  above the surface of water. ....... $cm$ will be the height of the jet of water coming from the orifice ? Velocity of water stream is $2.45 m/s$ 
A spherical liquid drop of radius $R$ is divided into eight equal droplets. If surface tension is $T$, then work done in the process will be:
A metal wire of length $0.5 m$ and cross-sectional area $10^{-4}\; m ^{2}$ has breaking stress $5 \times 10^{8}\; Nm ^{-2}$. A block of $10\; kg$ is attached at one end of the string and is rotating in a horizontal circle. The maximum linear velocity of block will be $ms ^{-1}$.
$Kilowatt - hour$ is a unit of
The average translational kinetic energy of ${N}_{2}$ gas molecules at $\ldots \ldots \ldots . .{ }^{\circ} {C}$ becomes equal to the ${K} . {E}$. of an electron accelerated from rest through a potential difference of $0.1$ $volt.$

$\left(\right.$ Given $\left.{k}_{{B}}=1.38 \times 10^{-23} \, {J} / {K}\right)$

(Fill the nearest integer).

On increasing number density for a gas in a vessel, mean free path of a gas
In case of an adiabatic process the correct relation in terms of pressure $p$ and density $\rho $ of a gas is
Newton's third law of motion leads to the law of conservation of
A $3\ kg$ sphere dropped through air has a terminal speed of $25\ m/s$. (Assume that the drag force is $-bv$.) Now suppose the sphere is attached to a spring of force constant $k = 300\ N/m$, and that it oscillates with an initial amplitude of $20\ cm$. What is the angular frequencu of its damped $SHM$? ..... $rad/s$