Power dissipated across the 8Ω resistor in the circuit shown here is 2 W. The power dissipated in watt units across the 3Ω resistor is
2.0
1.0
0.5
3.0
Faraday's laws are consequence of conservation of
Energy
Energy and magnetic field
Charge
Magnetic field
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
A heating coil is labelled 100 W, 220 V. The coil is cut in two equal- halves and the two pieces are joined in parallel to the same source. The energy now liberated per second is
25 J
50 J
200 J
400 J
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
Two 220 V, 100 W bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220 V AC supply line. The power drawn by the combination in each case respectively will be
200 W, 150 W
50 W, 200 W
50 W, 100 W
100 W, 50 W
A steady current of 1.5 A flows through a copper voltameter for 10 min. If the electrochemical equivalent of copper is 30 x 10-5 g C-1 the mass of copper deposited on the electrode will be
0.40 g
0.50 g
0.67 g
0.27 g
A current of 2 A, passing through a conductor produces 80 J of heat in 10 s. The resistance of the conductor in ohm is
2
4
20
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