MCQ
Which of the following are not electromagnetic waves ?
  • A
    cosmic rays
  • B
    $\gamma -$ rays
  • $\beta -$ rays
  • D
    $X-$ rays

Answer

Correct option: C.
$\beta -$ rays
c
$\beta -$ rays are the beam of fast moving electrons.

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

Which of these is a fusion reaction
A gamma ray photon creates an electron- positron pair. If the rest mass energy of an electron is $0.5\, MeV$ and the total $K.E.$ of the electron- positron pair is $0.78\, MeV$, then the energy of the gamma ray photon must be.......$MeV$
A particle $A$ has charge $+q$ and particle $B$ has charge $+4 q$ with each of them having the same mass $m$. When allowed to fall from rest through the same electric potential difference, the ratio of their speeds $\frac{V_A}{V_B}$ will become
Two electrons in an atom are moving in orbit of radii $R$ and $9R$ respectively. The ratio of their frequencies will be:
In an experiment of photoelectric effect the number of photoelectrons has to be increased without changing their frequency. The suitable step to be taken about the incident radiation for this is:
The current $I$, potential difference $V_L$ across the inductor and potential difference $V_C$ across the capacitor in circuit as shown in the figure are best represented vectorially as
How much energy in kilowatt hour is consumed in operating ten $50\, watt$ bulbs for $10$ hours per day in a month ($30$ days). 
As the $n$ (number of orbit) increases, the difference of energy between the consecutive energy levels
A bulb of 100 watt is hanging at a height of one meter above the centre of a circular table of diameter 4 m . If the intensity at a point on its rim is $I_0$, then the intensity at the centre of the table will be
An $\alpha -$ particle of $1\,MeV$ energy moves on circular path in uniform magnetic field. Then kinetic energy of proton in same magnetic field for circular path of double radius is......$MeV$