Two bulbs of $500\, W$ and $200\, W$ are manufactured to operate on a $220\, V$ line. What is the ratio of heat produced in the $500\, W$ bulb to the $200\, W$ bulb when they are connected in parallel,and when they are connected in series?

Find the percentage error in the reading of the voltmeter shown in the circuit. (in $\%$)

The thermo emf of a thermocouple is given by $E = aT + bT^2$,where $\frac{a}{b} = -200^{\circ}C$. If the cold junction is kept at $30^{\circ}C$,then the inversion temperature is ($\varepsilon$ in volt,$T$ in centigrade). (in $K$)

An ammeter $A$ of finite resistance and a resistor $R$ are joined in series to an ideal cell $C$. $A$ potentiometer $P$ is joined in parallel to $R$. The ammeter reading is $I_0$ and the potentiometer reading is $V_0$. $P$ is now replaced by a voltmeter of finite resistance. The ammeter reading now is $I$ and the voltmeter reading is $V$.

Pick out the wrong statement.

Suppose switches $S_1, S_2$ and so on up to $S_6$ are closed one after another in order (first $S_1$,then $S_2$,etc.) at regular intervals of $1 \text{ minute}$ starting from $t = 0$. The graph of current versus time is best represented as: