In the circuit shown in the figure,the power dissipated as heat in the $6\,\Omega$ resistor is $6\,W$. What is the value of resistance $R$ in the circuit? ................ $\Omega$

An electric bulb rated as $200 \, W$ at $100 \, V$ is used in a circuit having $200 \, V$ supply. The resistance $R$ that must be put in series with the bulb so that the bulb delivers the same power is $..... \, \Omega$.

If the ammeter in the given figure shows a reading of $2 \, A$,find the value of $R$ in $\Omega$.

$A$ wire of cross-section area $A$,length $L_1$,resistivity $\rho_1$ and temperature coefficient of resistivity $\alpha_1$ is connected to a second wire of length $L_2$,resistivity $\rho_2$,temperature coefficient of resistivity $\alpha_2$ and the same area $A$,so that the wires carry the same current. The total resistance $R$ is independent of temperature for small temperature changes if (Thermal expansion effect is negligible):

In the given circuit, what is the reading of the voltmeter in $V$?

$A$ voltmeter is connected in parallel with a variable resistance $R$ which is in series with an ammeter and a cell as shown in the figure. For one value of $R$,the meters read $0.3 \, A$ and $0.9 \, V$. For another value of $R$,the readings are $0.25 \, A$ and $1.0 \, V$. What is the internal resistance of the cell in $\Omega$?