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 ........... $W$

Three equal resistors connected in series across a source of $e.m.f.$ together dissipate $10\, watt$. If the same resistors are connected in parallel across the same $e.m.f.$, then the power dissipated will be .............. $watt$

A $100\, watt$ bulb working on $200 \,volt$ and a $200\, watt$ bulb working on $100\, volt$ have

A $500\, W$ heating unit is designed to operate from a $115\, volt$ line. If the line voltage drops to $110\, volt$, the percentage drop in heat output will be ............... $\%$

By what percentage will the illumination of the lamp decrease if the current drops by $20 \%$ ?

Two bulbs of $100\, W$ and $200\, W$ working at $220$ $volt$ are joined in series with $220$ $volt$ supply. Total power consumed will be approximately ........... $watt$