Electricity — Science STD 10 — Question

What kind of lens can form:

1. An inverted magnified image?
2. An erect magnified image?
3. An inverted diminished image?
4. An erect diminished image?

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?

Define the electric resistivity of material and also write its SI unit.

Draw ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed:

1. At 2 F₁
2. Between F₁ and the optical centre O of lens.

The diagram given alongside shows a ray of light entering a rectangular block of glass:

1. Copy the diagram and draw the normal at the point of entry.
2. Draw the approximate path of the ray of light through the glass block and out of the other side.

Why is LPG considered a good fuel?

Name two factors on which the resistivity of a substance depends and two factors on which it does not depend.

A convex lens forms a real and inverted image of a needle at a distance of 50 cm from it. Where is the needle placed in front of the convex lens if the image is equal to the size of the object? Also, find the power of the lens.

Name any two factors on which the strength of magnetic field produced by a current-carrying solenoid depends. How does it depend on these factors?