Light, Shadows And Reflections

Objects that give out or emit light of their own are known as luminous objects.

Translucent

Chair and shoe

True

If we are able to see clearly through an object, it is said to be transparent.

Glass and water

Sun and torch bulb

There are some objects through which we can see but not clearly. Such objects are known as translucent objects.

Opaque

Opaque

Plastic box and wooden table

Shadows are formed when an opaque object comes in path of light

True

Shape

We should not look directly at sun because that could be extremely harmful for the eyes.

Straight

True

Reflects

True

Opaque

Natural

Translucent

Inverted

Non luminous

Umbra and penumbra.

Transparent

True

Non luminous

a

Transparent

Sun

b

Transparent

Objects that emit light on their own are called luminous objects. The light emitted by luminous objects enables us to see things around us.

Objects that do not emit light on their own are called non-luminous objects. The light emitted by luminous objects falls on non-luminous objects, and then bounces back to our eyes, which enables us to see non-luminous objects.

Moon gets its light from the sun.

The light emitted by luminous objects falls on non-luminous objects, and then bounces back to our eyes, which enables us to see non-luminous objects.

We can see through windowpane. Objects through which we can see clearly are called transparent objects. Hence they are transparent objects.

Objects through which we can see clearly are called transparent objects. A medium that allows the entire light incident on it to pass through it is called a transparent

Electric bulb has its own light, so it is luminous object.

Ans: d.

Sun is the only natural luminous object.

Objects through which we cannot see anything are called opaque objects. A medium that does not allow light to pass through it is called an opaque medium.

Pure water is transparent. Rests are opaque objects.

Objects that do not emit light on their own are called non-luminous objects. The light emitted by luminous objects falls on non-luminous objects, and then bounces back to our eyes, which enables us to see non-luminous objects.

Frosted glass is translucent while rests are transparent.

Therootsare

A medium that allows the entire light incident on it to pass through it is called a transparent medium.

A medium that allows only a part of the light incident on it to pass through it is called a translucent medium.

A shadow is a dark patch formed behind an opaque object when it is placed in the path of light. A shadow is formed only when a light source, an opaque object and a screen are present.

A shadow is a dark patch formed behind an opaque object when it is placed in the path of light. A shadow is formed only when a light source, an opaque object and a screen are present.

The sun acts as the light source, the earth as the opaque object, and the moon as the screen.

All of the above follows rectilinear propagation of light.

Region has total eclipse

Shadow of moon falls on earth and blocks the sun. On this day sun cannot be seen.

Region has partial eclipse

Shadows show the outline of object.

Translucent Objects block light only partially, so they make faint shadows.

The size and shape of the shadow depends on the position and orientation of the opaque object between the source of light and the screen.

Ans: b.

The size and shape of the shadow depends on the position and orientation of the opaque object between the source of light and the screen. Cylindrical shape will form circular shade when light falls on circular part while when other side faces the sun rectangular shape is formed.

A shadow is a dark patch formed behind an opaque object when it is placed in the path of light. A shadow is formed only when a light source, an opaque object and a screen are present.

The pinhole camera works on the principle that light travels in a straight line. The image formed by a pinhole camera is real, inverted and diminished in size when compared to the original object.

The pinhole camera works on the principle that light travels in a straight line. The image formed by a pinhole camera is real, inverted and diminished in size when compared to the original object.

The image formed by a pinhole camera is real, inverted and diminished in size when compared to the original object.

Rectilinear propagation of light

Ans: c.

Ans: d.

Ans: b.

Ans: a.

Any kind – 35mm, 120, 220, large format, black and white or color or even IR – so long as it works with your camera, it’ll work for pinhole.

Reciprocity failure is when reciprocal relationship breaks down and doubling the exposure time no longer doubles the exposure.

Ans: b.

Ans: d.

Ans: c.

Ans: c.

Ans: d.

Ans: b.

Image is formed when light is reflected back from an object.

Reflected ray are reflected back at different angles, depending on angles they fall on. This is called diffused reflection.

Ans: a.

Ans: d.

The phenomenon of bouncing back of light after falling on the surfaces of the objects is called reflection of light.