A standard 12 V car battery has an ampere-hour rating of 40 Ah, whereas a heavy-duty battery has a rating of 60 Ah. How would you compare the energy levels of each and the available current for starting purposes?

Explanation:

Ah is a unit of charge .

A battery with 12 V and charge capacity of 40 Ah will have energy content

= volt x charge

volt = 12 V

Charge = 40 Ah

= 40 x 60 x 60 A.s

= 144000 coulomb

energy  content = 12 x 144000

= 1728000 J

energy content of heavy duty battery

= 12 x 60 x 60 x 60

= 2592000 J

Ratio = 1728000 / 2592000

= 2 / 3

Current can not be compared as current depends upon the resistance of appliance used . As resistance of appliance is unknown , current can not be compared.

your answer is c! hope this : )