A battery of internal resistance $4\,\Omega $ is connected to the network of the resistance as shown in Fig. If the maximum power can be delivered to the network, the magnitude of $R$ in $\Omega $ should be

In the circuit diagram shown, each battery is ideal having an e.m.f. of $1\  volt$. Each resistor has a resistance of $1\Omega $ Ammotor$(A)$ has a resistance of $1\Omega $ Find the reading of the ammeter and the total thermal power produced in the circuit 

A $25\, watt$, $220\, volt$ bulb and a $100\, watt$, $220\, volt$ bulb are connected in series across a $220\, volt$ lines. Which electric bulb will glow more brightly

Four equal resistance dissipated $5 \,W$ of power together when connected in series to a battery of negligible internal resistance. The total power dissipated in these resistance when connected in parallel across the same battery would be ........... $W$

Water fall from a $40\,m$ high dam at the rate of $9 \times 10^{4}\,kg$ per $hour$. Fifty percentage of gravitational potential energy can be converted into electrical energy. Using this hydroelectric energy number of $100\,W$ lamps, that can be lit, is

(Take $\left.g=10\,ms ^{-2}\right)$

A current of $2\, A$ passing through conductor produces $80\, J$ of heat in $10$ seconds. The resistance of the conductor is ............ $\Omega$