In a solar panel, solar beam is concentrated by using

Analysis

The question asks for the optical device used to concentrate solar beams in a solar panel system. To "concentrate" light means to bring parallel rays of light to a single point (a focus).

Concept Explanation

• Concave Mirrors (Converging Mirrors): These mirrors are curved inwards. When parallel rays of light (like sunlight) strike the surface of a concave mirror, they are reflected and converge at a single point called the principal focus. This property makes them ideal for collecting and concentrating solar energy to generate heat or electricity.
• Convex Mirrors (Diverging Mirrors): These mirrors curve outwards. They cause parallel rays of light to spread out (diverge) after reflection. They are used for security mirrors or side mirrors in cars because they provide a wider field of view, not for concentration.
• Plane Mirrors: These are flat mirrors. They reflect light at the same angle it hits them without converging or diverging the rays.
• Triangular Mirrors: This is not a standard optical term for light concentration; it refers to the shape of the glass rather than its reflective property.

Step-by-Step Solution

1. Identify the goal: We need to focus solar energy into a small area to increase intensity.
2. Evaluate the physics: Concentration requires a converging surface.
3. Apply the principle: A concave mirror acts as a converging mirror. By placing a solar collector at the focal point of a concave mirror, all the light hitting the mirror is directed onto that single point, significantly increasing the energy density.
4. Conclusion: Because concave mirrors converge parallel light rays to a focal point, they are the standard choice for solar concentrators.

Correct Answer

The correct option is A.

Exam Tip

Think of the word "Concave" as "Cave". Just as you go into a cave to gather together in one spot, a concave mirror gathers light rays into one spot (the focus). This memory trick will help you remember that concave mirrors converge light, while convex mirrors diverge it!