A $220\, volt$ and $800\, watt$ electric kettle and three $220\, volt$ and $100\, watt$ bulbs are connected in parallel. On connecting this combination with $220\, volt$ electric supply, the total current will be ................ $ampere$

Model a torch battery of length $l$ to be made up of a thin cylindrical bar of radius $'a'$ and a concentric thin cylindrical shell of radius ' $b$ ' fille in between with an electrolyte of resistivity $\rho$ (see figure). If the battery is connected to a resistance of value $R ,$ the maximum Joule heating in $R$ will take place for

A battery is charged at a potential of $15\, V$ for $8$ hours when the current flowing is $10\, A$. The battery on discharge supplies a current of $5\, A$ for $15$ hours. The mean terminal voltage during discharge is $14\, V$. The "Watt-hour" efficiency of the battery is .............. $\%$

A $25\, W$, $ 220\, V$ bulb and a $100\, W$, $220\, V$ bulb are connected in parallel across a $440\, V$ line

A battery of internal resistance $4\, ohm$ is connected to the network of resistance as hown.  In the order that the maximum power can be delivered to the network, the value of $R$ in ohm should be :-

In the circuit shown below, the power developed in the $6$ $\Omega$ resistor is $6\, watt$. The power in watts developed in the $4$ $ \Omega$ resistor is