An electric kettle takes 4 A current at 220 V. How much time will it take to boil 1 kg of water from temperature 20oC ? (The temperature of boiling water is 100oC)
6.3 min
8.4 min
12.6 min
4.2 min
Three equal resistors connected in series across a source of emf together dissipate 10 W of power. What will be the power dissipated in watt if the same resistors are connected in parallel across the same source of emf?
W
10W
30W
90W
In electrolysis the mass deposited on an electrode is directly proportional to
Current
Square of current
Concentration of solution
Inverse of current
Two identical batteries each of emf 2 V and internal resistance 1 Ω 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
3.2 W
2.0 W
1.28 W
The total power dissipated in watts in the circuit shown here is
16
40
54
4
In India electricity is supplied for domestic use at 220V.It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be
R
2R
A 5 A fuse wire can withstand a maximum power of 1 W in a circuit. The resistance of the fuse wire is
0.2 Ω
5 Ω
0.4 Ω
0.04 Ω
Direct current is passed through a copper sulphate solution using platinum electrodes. The elements liberated at the electrodes are
Copper at anode and sulphur at cathode
Sulphur at anode and copper at cathode
Oxygen at anode and copper at cathode
Copper at anode and oxygen at cathode
In producing chlorine through electrolysis 100 W power at 125 V is being consumed. How much chlorine per minute is liberated ? (ECE of chlorine is 0.367 x 10-6 kg/C)
17.6 mg
21.3 mg
24.3 mg
13.6 mg
Faraday's laws are consequence of conservation of
Energy
Energy and magnetic field
Charge
Magnetic field
