A stream of electrons and protons are directed towards a narrow slit in a screen (see figure). The intervening region has a uniform electric field (vertically downwards) and a uniform magnetic field $\mathbf{B}$ (out of the plane of the figure) as shown. Then

• A

  electrons and protons with speed $\frac{|\mathrm{E}|}{|\mathbf{B}|}$ will pass through the slit
• B

  protons with speed $|\mathrm{E}| /|\mathrm{B}|$ will pass through the slit, electrons of the same speed will not
• Correct answer
  C

  neither electrons nor protons will go through the sit irrespective of their speed
• Correct answer
  D

  electrons will always be deflected upwards irrespective of their speed

Solution

of their speed. And electrons will always be deflected upwards irrespective of their speed. So, (c) and (d) are correct options.

Hence, the correct answer is options: 'C', 'D'.