$A$ constant voltage is applied between the two ends of a uniform metallic wire. Some heat is developed in it. The heat developed is doubled if

Which one is not the correct statement

A coil takes $15\,\min$ to boil a certain amount of water, another coil takes $20\,\min$ for the same process. Time taken to boil the same amount of water when both coil are connected in series ........... $min$

In the following circuit, the battery has an emf of  $2\mathrm{V}$ and an internal resistance of $\frac{2}{3}\  \Omega$. The power consumption in the entire circuit is$..... W.$

When two identical batteries of internal resistance $1 \Omega$ each are connected in series across a resistor $\mathrm{R}$, the rate of heat produced in $R$ is $J_1$. When the same batteries are connected in parallel across $R$, the rate is $\mathrm{J}_2$. If $\mathrm{J}_1=2.25 \mathrm{~J}_2$ then the value of $\mathrm{R}$ in $\Omega$ is

In the circuit shown in figure, if ammeter and voltmeter are ideal, then the power consumed in $9 \,\Omega$ resistor will be .......... $W$