If power in $3\,\Omega $ is $27\,W$ then what is the power in $2\,\Omega $ ................ $\mathrm{W}$
$8$
$16$
$12$
$15$
Electric bulb $50\, W$ - $100\, V$ glowing at full power are to be used in parallel with battery $120\, V$, $10 \,\Omega$. Maximum number of bulbs that can be connected so that they glow in full power is
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$..... W.$
An electric kettle has two coils. When one of these is switched on, the water in the kettle boils in $6\,\min$ . When the other coil is switched on, the water boils in $3\,\min$. If the two coils are connected in series, the time taken to boil the water in the kettle is ............. $min$
$A\,\,{5\,^o}C$ rise in the temperature is observed in a conductor by passing some current. When the current is doubled, then rise in temperature will be equal to ............. $^oC$
Four wires of the same diameter are connected in turn between two points, maintained at a constant potential difference. Their resistivities are; $\rho $ and $L$ (wire $1$ )., $1.2\,\rho $ and $1.2\,L$ (wire $2$ ), $0.9\,\rho $ and $0.9\,L$ (wire $3$ ) and $\rho $ and $1.5\,L$ (wire $4$ ). Rank the wires according to the rates at which energy is dissipated as heat, greatest first