Current Electri...

A current of 1.5 A flows through a wire for 30 minutes, when the potential difference across its ends is 10 V. The heat produced is

The water in an electric kettle begins to boil in 15 minutes after being switched on. Using the same mains supply, should the length of the wire used as the heating element be increased or decreased if the water is to boil in 10 minutes?

The three resistance A, B and C have values R, 3 R and 6 R respectively. When some Potential difference is applied across the net work, the thermal power dissipated by A, B and C are in the ratio

Four resistances carrying a current shown in the circuit diagram Fig. are immersed in a box containing ice at 0ºC. How much ice must be put in the box every 10 minutes to keep the average quantity of ice in the box constant. (Latent heat of ice is 80 Cal/gm)

Two identical batteries each of e.m.f. 2 V and internal resistance 1Ω are available to produce heat in an external resistance by passing a current through it. The maximum power that can be developed across R using these batteries is

Twenty electric bulbs are connected in series across a 220 V supply and the illumination produced is I₁. Five bulbs are fused. If the remaining 15 bulbs are again connected in series, the illumination produced is I₂. Then

Which of the following is not the advantage of alkali cells over acid cells?

If a current of 2 A liberates a certain amount of ions, a current of 8 A will liberate

A copper voltameter and a silver voltameter are connected in series in a circuit. The rate of the increase in the weight of the cathode in the two voltameters will be in the ratio of

A lead acid accumulator (storage battery) is connected to a battery charger for over night charging. Which of the following observations will indicate that the battery was partly charged during the next morning