there are 332kj in diesel!!!!!!
The amount of energy will vary depending on the quality of the petrol but a good estimate is 32MJ per litre. So that's 32kJ in 1ml.
One joule = 0.2388459 calories.
That varies. Look at the radio's specifications - most pieces of electrical equipment have the information quite visible, perhaps on the back of the radio. It may give you an amount of watts, or...
Depends how much wood it contains
It depends what type of chemical energy it is. But if it is just in general, then you would do nothing ,you would just leave it the same.