The white light splits up in 7 colours, which is called dispersion. Therefore, option (2) is correct.

Opaque things - Do not allow the light to pass through Transparent objects - Transmit the light Translucent objects - A part of light can pass Wall - opaque, Glass - transparent and Tracing paper - translucent Therefore, option (3) is correct.

Initial reading of electric meter = 4750 KWhFinal reading of electric meter = 4930 KWhTotal energy consumed during the month = 4930 - 4750 = 180 KWh = 180 unitsCost of 1 unit = Rs 2.50Total cost of 180 units = 180 * 2.50       = Rs 450

The Moon doesn’t have its own light.

If we add seven colours of rainbow, and make them pass through a prism, they will deviate the white light.

Air is transparent and not translucent.

Pinhole camera is based on the rectilinear propagation of light, i.e. the property that light travels in straight lines.

Glass is transparent.

Luminous objects are those, which emit light of their own. Therefore option (2) is correct.

Plastic is translucent and not transparent.

Opaque object causes shadow when light falls on them.

The fact that light travels in a straight line accounts for the occurrence of Eclipses.

Image will be formed, which will be inverted and also will be turned upside down and also will be turned left to right. It is based on the property of rectilinear propagation of light.

When Earth comes between the sun and the moon, the shadow of the earth falls on the moon. No sunlight can reach to the moon. So, option (1) is correct.

Through the left, the 7 colours of rainbows are written as ROYGBIV, and the 3^rd colour to the left from blue is orange.

Moon is not a light source. It reflects light falling on it whereas the rest are sources of light.