B M Sharma Solutions for Chapter: Heating Effects of Current, Exercise 1: DPP

Two bulbs of $500 \mathrm{W}$ and $200 \mathrm{W}$ are manufactured to operate on $220 \mathrm{V}$ line. The ratio of heat produced in $500 \mathrm{W}$ and $200 \mathrm{W}$, in two cases, when first they are joined in parallel and second in series, will be:

Two wires $A$and $B$of the same material have their lengths in the ratio $1:2$and radii in the ratio $2:1.$The two wires are connected in parallel across a battery. The ratio of the heat produced in $A$ to the heat produced in $B$for the same time is

Two wires $A$and $B$of the same material and mass have their lengths in the ratio $1:2.$On connecting them to the same source, the rate of heat dissipation in $B$is found to be $5 \mathrm{W}.$The rate of heat dissipation in $A$is

An electric kettle has two heating coils. When one coil is used, water in the kettle boils in $5$$\min$, while when the second coil is used, the same water boils in $10$$\min$. If the two coils connected in parallel are used simultaneously, the same water will boil in

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

If the resistance of the filament increases with temperature, what will be power dissipated in a $220 \mathrm{V}-100 \mathrm{W}$lamp when connected to a $110 \mathrm{V}$power supply?

Two bulbs consume same power when operated at $200 \mathrm{V}$and $300 \mathrm{V}$respectively. When these bulbs are connected in series across a $\mathrm{D}.\mathrm{C}.$ source of $500 \mathrm{V}$, then,

A steel wire has a resistance twice that of an aluminium wire. Both of them are connected with a constant voltage supply. More heat will be dissipated in: