Do I have a good ear for music?

Well basically I want to know if I have a good ear for music. As I'm learning guitar. I learned the G major scale on the guitar then I went to a friends house he had this south American ukulele ( four stringed mini guitar) on a different guitar tuning. He is a professional musician and tested me to see if I could play the G major scale (pattern 1) on the guitar and I took about 20 secs and figured it out. Do I have a good ear? I just wanna know to boost my motivation and are there any test on the net to find out for my self?