Fill in the following blanks with suitable words :
A concave lens ___________ parallel rays of light whereas a convex lens _____________ parallel rays of light.

Answer

To fill in the blanks in the given statement, we need to understand the behavior of concave and convex lenses with respect to parallel rays of light.

1. **Understanding Concave Lens**: A concave lens is known as a diverging lens. When parallel rays of light pass through a concave lens, they spread out or diverge. This means that the rays do not converge to a point but instead move away from each other.

2. **Understanding Convex Lens**: A convex lens, on the other hand, is known as a converging lens. When parallel rays of light pass through a convex lens, they converge or come together at a point known as the focus. This means that the rays meet at a specific point after passing through the lens.

Now, we can fill in the blanks:

- A concave lens **diverges** parallel rays of light whereas a convex lens **converges** parallel rays of light.

### Final Answer:
A concave lens **diverges** parallel rays of light whereas a convex lens **converges** parallel rays of light.