The cyclotron is a device which is used to accelerate charged particles such as protons, deutrons, alpha particles, etc. to very high energy. The principle on which a cyclotron works is based on the fact that an electric field can accelerate a charged particle and a magnetic field can throw it into a circular orbit. A particle of charge `+q` experiences a force qE in an electric field E and this force is independent of velocity of the particle. The particle is accelerated in the direction of the magnetic field. On the other hand, a magnetic field at right angles to the direction of motion of the particle throws the particle in a circular orbit in which the particle revolves with a frequency that does not depend on its speed. A modest potential difference is used as a sources of electric field. If a charged particle is made to pass through this potential difference a number of times, it will acquire an enormous by large velocity and hence kinetic energy.
Which of the following cannot be accelerated in a cyclotron?

Options

A. Protons
B. Deutrons
C. Alpha particles
D. Neutrons

Answer

To determine which particle cannot be accelerated in a cyclotron, we need to analyze the nature of the particles mentioned and their charge properties. Here’s a step-by-step solution:

### Step 1: Understand the working principle of a cyclotron
A cyclotron accelerates charged particles using an electric field and a magnetic field. The electric field accelerates the particles, while the magnetic field causes them to move in a circular path.

### Step 2: Identify the types of particles mentioned
The question refers to several types of particles:
- Protons
- Neutrons
- Alpha particles

### Step 3: Determine the charge of each particle
- **Protons**: Protons have a positive charge (+q).
- **Neutrons**: Neutrons have no charge (0).
- **Alpha particles**: Alpha particles consist of 2 protons and 2 neutrons, thus they have a positive charge (+2q).

### Step 4: Analyze which particle can be accelerated
Since the cyclotron works on the principle of accelerating charged particles:
- Protons can be accelerated because they are charged.
- Alpha particles can also be accelerated because they are charged.
- Neutrons cannot be accelerated because they have no charge.

### Conclusion
The particle that cannot be accelerated in a cyclotron is the neutron.

### Final Answer
**Neutrons cannot be accelerated in a cyclotron.**

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