Which of the following is deflected by electric field ?

Options

A. X-rays
B. `gamma-`rays
C. Neutrons
D. `alpha-`particles

Answer

To determine which of the following is deflected by an electric field, we need to analyze the nature of the particles mentioned in the question. The key point to remember is that only charged particles will experience a force in an electric field and thus will be deflected.

### Step-by-Step Solution:

1. **Understanding Electric Fields**: Electric fields exert forces on charged particles. The force \( F \) experienced by a charged particle in an electric field \( E \) is given by the equation:
\[ F = qE \]
where \( q \) is the charge of the particle.

2. **Identifying Charged and Neutral Particles**: We need to identify which of the given options are charged. Charged particles will be deflected, while neutral particles will not.

3. **Analyzing the Options**:
- **Option 1: X-rays** - X-rays are a form of electromagnetic radiation and are electrically neutral. They do not have any charge and therefore will not be deflected by an electric field.
- **Option 2: Gamma rays** - Similar to X-rays, gamma rays are also electromagnetic radiation and are neutral. They will not be deflected by an electric field.
- **Option 3: Neutrons** - Neutrons are subatomic particles found in the nucleus of an atom and are electrically neutral. They will not experience any force in an electric field.
- **Option 4: Alpha particles** - Alpha particles are positively charged particles (specifically, they are helium nuclei, which consist of 2 protons and 2 neutrons, giving them a +2 charge). They will be deflected by an electric field.

4. **Conclusion**: Based on the analysis, the only particles that will be deflected by an electric field are the alpha particles.

### Final Answer:
The correct option is **Option 4: Alpha particles**.

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