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In the circuit shown, resistors $A$, $B$ and $C$ are identical. When $K$ is open, the power dissipated by $A$ is $P_1$. When $K$ is closed, the power dissipated by $A$ becomes $P_2$. The ratio $P_1:P_2$ is equal to

In the circuit shown, a $4\ \Omega$ resistor is to be connected to two of the terminals $A$, $B$, $C$ and $D$ to give the greatest brightness in the light bulb. Which connection should be made ?

Two copper wires, $A$ and $B$, of the same length have the ratio of mass of $4:9$. Assuming the cross-sections are uniform, what is the ratio of the resistance of $A$ to that of $B$ ?

In the circuit above, the two resistors are identical. When the switch $K$ is closed, what happens to the readings of the ammeter $A$ and the voltmeter $V$ ?

In the circuit shown, the energy required by an electron to travel from $Q$ to $P$ through $X$ is $E_1$ and that through $Y$ is $E_2$. Which of the following is correct ?

What should be the potential difference between $P$ and $Q$ in the circuit shown ?

In the circuit shown, which of the switches should be closed in order to get the maximum brightness in lamp $L$ ?

Four identical lamps $P$, $Q$, $R$ and $S$ are connected to a battery as shown above. If lamp $P$ is blown, which of the following would happen ?

In the circuit shown, all resistors are the same. If the current passing point $X$ is $1$ A, what will be the current delivered from the battery ?

The above circuit shows two resistors $R_1$ and $R_2$ connected in series to a battery. The resistance of $R_1$ is greater than that of $R_2$. The ends of the resistors are marked $P$, $Q$, $R$ and $S$. Which of the graphs best shows how the potential $V$ varies along $PS$ ?