Which of the following particles cannot be accelerated by an electric or magnetic field?

Cathode rays are

Arrange the $\frac{e}{m}$ (charge-to-mass) ratio in increasing order for the following particles: $e, p, n, \alpha$.

Neutrons are obtained by

Which particle leaves no track in a Wilson cloud chamber?

Fill in the blanks given below:
$(i)$ The picture on the television screen is visible due to the presence of .......... on the screen.
$(ii)$ In the presence of electric and magnetic fields,cathode rays are known as .......... .
$(iii)$ The measurement of the $e/m_e$ ratio for electrons was performed by the scientist .......... .
$(iv)$ In a cathode ray tube,the greater the magnitude of the charge on the particles,the .......... the deflection of the particles.