A piece of fuse wire melts when a current of $15\, ampere$ flows through it. With this current, if it dissipates $22.5\, W$, the resistance of fuse wire will be .............. $\Omega$

An electric lamp is marked $60\, W$, $230\, V$. The cost of a $1\, kWh$ of energy is Rs. $1.25$. The cost of using this lamp $8$ hrs a day for $30$ day is Rs. ...............

An electric heater consists of a nichrome coil and runs under $220 \,V$, consuming $1 \,kW$ power. Part of its coil burned out and it was reconnected after cutting off the burnt portion.The power it will cunsume now is

A bulb has specification of one kilowatt and $250\, volts$, the resistance of bulb is .................. $\Omega$

The electric current passing through a metallic wire produces heat because of

Two resistances ${R_1}$ and ${R_2}$ when connected in series and parallel with $120\, V$ line, power consumed will be $25\, W$ and $100\, W$ respectively. Then the ratio of power consumed by ${R_1}$ to that consumed by ${R_2}$ will be