A device that converts the energy of combustion of fuels, like hydrogen and methane, directly into electrical energy is known as:
1. | Fuel cell. | 2. | Electrolytic cell. |
3. | Dynamo. | 4. | Ni-Cd cell. |
If a salt bridge is removed from the two half cells, the voltage:
1. Drops to zero.
2. Does not change.
3. Increases gradually.
4. Increases rapidly.
The efficiency of a fuel cell is given by:
1.
2.
3.
4.
If hydrogen electrodes dipped in two solutions of pH = 4 and pH = 6 are connected by a salt bridge, the emf of the resulting cell is -
1. 0.177 V
2. 0.3 V
3. 0.118 V
4. 0.104 V
When a lead storage battery is discharged, then:
1. SO2 is evolved.
2. Lead is formed.
3. Lead sulphate is consumed.
4. Sulphuric acid is consumed.
A depolariser used in dry cell batteries is:
1. Ammonium chloride
2. Manganese dioxide
3. Potassium hydroxide
4. Sodium phosphate
1. | PbSO4 anode is reduced to Pb. |
2. | PbSO4 cathode is reduced to Pb. |
3. | PbSO4 cathode is oxidised to Pb. |
4. | PbSO4 anode is oxidised to PbO2. |