Chapter 16, Problem 31A

To determine

To Find: Whether a frosted, incandescent bulb is a luminous source or an illuminated object.

Explanation of Solution

Introduction:

Objects which itself can emit light energy are known as luminous objects. Sun is a luminous source.

Objects that simply cannot emit light energy are known as non-luminous objects. Moon is an illuminated object.

In a bulb,the filament is heated when current is passed through it and then it becomes incandescent. Due to heating, this filament emits the light. As the filament emits the light so it is considered as a luminous source. The frosted glass is visible due to reflection of the light emitted from the filament.

Conclusion:

Hence, frosted glass is considered as an illuminated source.