$B_1, B_2$ and $B_3$ are three identical bulbs connected as shown in the figure. When all three bulbs glow,a current of $3\,A$ is recorded by the ammeter $A$.
$(i)$ What happens to the glow of the other two bulbs when the bulb $B_1$ gets fused?
$(ii)$ What happens to the reading of $A_1, A_2, A_3$ and $A$ when the bulb $B_2$ gets fused?
$(iii)$ How much power is dissipated in the circuit when all three bulbs glow together?

An electric oven hot plate is connected to a $200 \, V$ line. It has two resistance coils $A$ and $B$,each of $30 \, \Omega$,which may be used separately,in series,or in parallel. Find the value of the current required in each of the three cases.

Draw a schematic diagram of an electric circuit (in the "on" position) consisting of a battery of five cells of $2\, V$ each, a $5\, \Omega$ resistor, a $8\, \Omega$ resistor, a $12\, \Omega$ resistor and a plug key, all connected in series. An ammeter is put in the circuit to measure the electric current through the resistors and a voltmeter is connected so as to measure the potential difference across the $12\, \Omega$ resistor.
Calculate the reading shown by the
$(a)$ ammeter
$(b)$ voltmeter in the given electric circuit.

Which of the following is the symbol for a resistor?

$(a)$ Explain the difference between direct current and alternating current. Write one important advantage of using alternating current.
$(b)$ An air conditioner of $2 \,kW$ is used in an electric circuit having a fuse of $10 \,A$ rating. If the potential difference of the supply is $220 \,V$,will the fuse be able to withstand the current when the air conditioner is switched on? Justify your answer.

Read the following statements carefully and state whether each statement is true or false:
$(i)$ The quantity of charge flowing past a point multiplied by time is current.
$(ii)$ The flow of charge through a conducting wire connected to a cell is the result of a chemical reaction inside the cell.
$(iii)$ The resistivity of all pure metals increases with an increase in temperature.
$(iv)$ Ohm's law is a relation between the power used in a circuit to the current and the potential difference.
$(v)$ $A$ series circuit has only one conducting path for the electrons that move through it; a parallel circuit has multiple conducting paths.
$(vi)$ $A$ conducting wire offers resistance to the flow of electrons because electrons repel each other in the wire.