1st generation explosive reactive armour?

Actually I have 2 questions.

1) Does the 1st generation explosive reactive armour (ERA) explode, when it is hit by machinegun (7,62mm) or HMG (12,7mm) bullets?

2) I want to know, how big effect is for the MBT (T-72/T-90) crew, when MBT is hit by ATGM (or ATGL) and warhead does not penetrate the armour?


As you all can see, my English is not very good�.so don�t make any jokes on me