Which of the following statements is true?
1
The average EMF of the nickel-cadmium battery is 6.2 V per cell
2
The average EMF of the nickel-cadmium battery is 2.5 V per cell
3
A nickel-cadmium battery is superior as compared to a lead-acid battery
4
A lead-acid battery is superior as compared to a nickel-cadmium battery