Tungsten is used almost exclusively for filaments of electric bulbs. List two reasons.

What are the factors on which the resistivity of a material depends?

Draw a labelled circuit diagram showing three resistors $R_{1}, R_{2}$ and $R_{3}$ connected in series with a battery $(E)$,a rheostat $(Rh)$,a plug key $(K)$ and an ammeter $(A)$ using standard circuit symbols. Use this circuit to show that the same current flows through every part of the circuit. List two precautions you would observe while performing the experiment.

Why are alloys commonly used in electrical heating devices?

Which of the following is $NOT$ a unit of electrical energy?

$(a)$ Explain why a conductor offers resistance to the flow of current.
$(b)$ Differentiate between conductor,resistor,and resistance.