Questions

The number of secondary windings in the coil of a transformer used in a microwave oven is 10 times the number of windings in the primary coil. If it is connected to a source of 220 V, what is the secondary voltage obtained from the transformer?

To charge a laptop of 20V, a charger with 550 primary turns is connected to an A.C. source of 220 V. Calculate the number of secondary windings of the charger.

Draw the block diagrams of the step-up transformer and step-down transformer and write two uses of each.

What is a transformer?

Prepare a research report on any two sources of electricity in Nepal (Hydro power station, Solar power plant) including their capacity, type of electricity produced, and transmission.

What can be done to increase the magnitude of current produced by a dynamo? Write any two ways.

A bulb connected to a dynamo attached to the tire of a bicycle is not found to be glowing with steady brightness. It was found that the bulb was bright, dimmed, and also turned off when the cycle came to rest. Mention the reasons for such observations based on the working principle of dynamo.

State Faraday's law of electromagnetic induction.

What is electromagnetic induction?

The power of the lens used in the spectacles worn by a student is -6 D. Calculate the focal length of the lens. Also, mention the type of lens.