would what the nature of the shadow on the floor be if the point of source of light is replaced by a luminous disc of diameter 5 cm, whose centre lies directly above the centre of the card?
You'll get better responses if you follow directions and put the SUBJECT in the School Subject line.
And DO NOT post entire questions in all-capital letters.
You would also help yourself by telling what you do and don't understand about the assignment.
I did this penumbra question where you asked it first below.
thank you
To determine the nature of the shadow on the floor, we need to consider the properties of light and how it interacts with objects.
Since the luminous disc has a diameter of 5 cm and its center lies directly above the center of the card, the light emitted from the disc will spread out in all directions. This spreading of light is known as diffraction.
When the light from the disc reaches the card, it will cast a shadow. The nature of the shadow will depend on the distance between the card and the floor, as well as the relative sizes of the objects involved.
If the card is relatively small compared to the disc, the shadow on the floor will appear as a distinct shape, resembling the outline of the card. The edges of the shadow will be sharp and well-defined.
However, if the card is large compared to the disc, the size of the shadow on the floor may be influenced by the disc's diameter. In this case, the shadow may appear slightly blurred or diffuse around the edges due to the spreading of light by diffraction.
To get a more precise understanding of the nature of the shadow, you can perform an experiment. Set up the luminous disc above the card and observe the shadow cast on the floor. Adjust the distance between the card and the floor, as well as the position and intensity of the light source, to observe any variations in the shadow's characteristics.