Which of the following is/are not always necessary to observe a shadow?
(a) Sun
(b) Screen
(c) Source of light
(d) Opaque object
Which of the following is/are not always necessary to observe a shadow?
Answer:
To observe a shadow, certain elements are required. In this case, the (b) Screen is not always necessary to observe a shadow. While the presence of the sun, a source of light, and an opaque object are essential components for the formation of a shadow, a screen is not always mandatory. Shadows can be observed directly on surfaces without the need for a specific screen to capture or display them. Screens are commonly used to enhance the visibility and clarity of shadows, but shadows can be observed without the aid of a screen in many situations.