If you have a broken arm,and in a cast, can you still take your drivers license test?
As long as your broken arm doesn't negatively impact your driving, yes you can.
Even though most people drive with one hand, we are taught in drivers Ed that both hands need to be on the wheel. Just call the DMV to double check.
I would wait. It will make it easier for you. For some people it's hard and stressful enough to take a drivers test without any injury. Much less with a broken arm. I hope it gets better soon! :)
Can you put your hands at "ten and two"? That's a biggie. What did your doctor say about driving?