Question

An electric field can deflect
A. Neutrons
B. X-rays
C. $\gamma $-rays
D. $\alpha $-rays

Answer 1

Hint: For the particle to be deflected by an electric field, it has to have the fundamental property of charge in it so that due to the electric field, a force acts on it due to which it changes its trajectory.
Neutrons are subatomic particles having no charge means they are neutral.
X -rays and $\alpha $-rays are electromagnetic radiation formed from particles of light called photons.
$\alpha $-rays actually consist of a helium nucleus which is charged.

Complete step by step answer:
Any particle which is deflected by an external electric field, is due to charge on the particle due to which it experiences force.
Neutrons which form the majority of an atom's nucleus are uncharged particles unlike protons and neutrons and hence pass undeflected from any external electric field.
X-rays and gamma $\gamma $rays are high frequency electromagnetic radiation which is a form of light formed from particles called photons and photons are uncharged particles and hence these two rays also pass undeflected from the electric field.
$\alpha $-rays consists of helium nucleus $\left( {}_{2}^{4}He \right)$and hence consist of charged particles due to which it experiences force when present in any external electric field and gets deflected.

So, the correct answer is “Option D”.

Note: Electromagnetic radiation constitutes a spectrum of radiations from $\gamma $rays having highest frequency to radio waves having lowest frequency.
Neutrons along with protons form a major constituent atom with electrons rotating around in orbits.
As $\alpha $-rays are charged particles, they are also deflected by magnetic fields.