MCQ
Frequency of a wave is $6 \times {10^{15}}Hz.$ The wave is
  • A
    Radiowave
  • B
    Microwave
  • C
    $X-$ ray
  • None of these

Answer

Correct option: D.
None of these
d
$f=6 \times 10^{15}\,Hz$

$\lambda=\frac{c}{f}=\frac{3 \times 10^8}{6 \times 10^{15}}\,m$

$m \lambda=5 \times 10^{-8}\,m$

for, $10^{-8} m < \lambda < 10^{-11} m$ it is $x$-ray

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

The magnetic induction in air at a distance $d$  from an isolated point pole of strength $ m$  unit will be
The resultant of two rectangular simple harmonic motions of the same frequency and unequal amplitudes but differing in phase by $\frac{\pi }{2}$ is
The position vector of a particle is determined by the expression $\vec r = 3{t^2}\hat i + 4{t^2}\hat j + 7\hat k$ The distance traversed in first $10 \,sec$ is........ $m$
Four identical particles of mass $m$ are kept at the four corners of a square. If the gravitational force exerted on one of the masses by the other masses is $\left(\frac{2 \sqrt{2}+1}{32}\right) \frac{\mathrm{Gm}^2}{\mathrm{~L}^2}$, the length of the sides of the square is
Two identical satellites are at $R$ and $7R$ away from earth surface, the wrong statement is ($R $ = Radius of earth)
The diagram shows magnetic field lines. We move from above to below and back.Below shows the graph of variaton of magnetic flux with time. We will measure the flux of
If a cylinder of diameter $1.0\, cm$ at $30°C$ is to be solid into a hole of diameter $0.9997\, cm$ in a steel plate at the same temperature, then minimum required rise in the temperature of the plate is ........ $^oC$ (Coefficient of linear expansion of steel $ = 12 \times {10^{ - 6}}°C^{-1}$)
Assertion : The maximum refractive index of liquid for total internal reflection of the ray passing through the prism as shown in figure must be $\sqrt 2$.
 
Reason: Here, critical angle is $45^o$

A length $L$ of wire carries a steady current $I$. It is bent first to form a circular plane coil of one turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current is
A battery is used to charge a parallel plate capacitor till the potential difference between the plates becomes equal to the electromotive force of the battery. The ratio of the energy stored in the capacitor and the work done by the battery will be