electrical previous year question

1)generally the mobility of electron in semiconductor is ........that of holes 

ans- 3 times

2)when a BJT is used as a switch its mode of operation switches between 

ans - cut off and saturation region

3)

what type of earthing is used in transmission line 

ans - strip earthing 

4) how many outlets are permitted in power circuits 

ans -two points 

Balram ki diary