What if the iPad charger is broken

Everything in the box is under the same warranty

if they judge it broke before of a production issue only discovered after purchase they will give you a new one

read

Legal - Hardware Warranties - Apple

otherwise you can purchase a new charger

If the device is still under 1 year warranty period, visit an Apple Store and have the charger replaced.

Shouldn't be this case, buy a new charger.

Regards

Giulio