Light – Reflection and Refraction — Science STD 10 — Question

What is the shape of field lines inside a current-carrying solenoid? What does the pattern of field lines inside a current-carrying solenoid indicate?

Draw a ray diagram to show the formation of a real diminished image of an object by a convex lens. In your diagram, the position of object and image with respect to the principal focus should be shown clearly.

What current will be taken by a 920W appliance if the supply voltage is 230V?

Write the conditions for observing a rainbow. Show, by drawing a suitable diagram, how one understands the formation of a rainbow?

The pollution of air caused by burning petroleum fuels (like petrol and diesel) in vehicles can be controlled by fitting a device X in the exhaust system of vehicles.

1. Name the device
2. How does this device help in controlling air pollution?

What is meant by:

1. Principal focus of a convex mirror.
2. Focal length of a convex mirror?

A person needs a lens of power, -5.5 dioptres for correcting his distant vision. For correcting his near vision, he needs a lens of power, +1.5 dioptres. What is the focal length of the lens required for correcting

1. Distant vision, and
2. Near vision?

Where must the object be placed for the image formed by a converging lens to be:

1. Real, inverted and smaller than the object?
2. Real, inverted and same size as the object?
3. Real, inverted and larger than the object?
4. Virtual, upright and larger than the object?

What happens to the eye when you enter a darkened cinema hall from bright sunshine? Give reason for your answer.

An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.