S N Jha, Geeta Negi and, Neelima Jain Solutions for Chapter: Electricity and Circuits, Exercise 3: EXERCISES

Give three differences between conductors and insulators. (In tabular form).

Give the construction, working and uses of a simple dry cell.

Give the construction, working and uses of an electric torch.

Figure alongside shows a cell connected to a bulb through insulating copper wires. State with a reason in which case the bulb will not glow.

Figure alongside shows a cell connected to a bulb through insulated copper wires. State with a reason in which case the bulb will glow.

Rahim used a piece of thread to connect the terminals A and B as shown in the figure. What will happen?

A circuit tester is shown below :

Classify the objects given below into ones that would make the bulb glow and those that would not.

Sanjay took a dry cell and connected to its central terminal to a copper wire, such that other end of the copper wire is free. The base of the cell was connected to another copper wire, whose other end is connected to a terminal of a flashlight bulb. The other terminal of the flashlight bulb is connected to another copper wire with free end. The free ends of the copper wires he connected to materials such as silver spoon, a brass candle stand, a steel plate, a plastic plate, an eraser, a rubber balloon, etc. He noticed that in the case of the first three materials the bulb glowed. However, in the case of the next three materials bulb did not glow. He wanted to know the reason behind it, so he contacted his friend Puneet. He explained such things on the basis of characteristics of conductor and insulator.

Answer the following question based on the above information:
What role do the above materials play in an electric circuit?