(i)its a circuit where b1,b2 & b3 are connected in parallel. hence,if b2 stops glowing other bulbs will continue to glow(as each bulb has its own switch).
given: 3A is recorded by A when all bulbs are glowing.
so if 1bulb (b2) stops glowing :
a1 will show 1A,
a2 will show 0 - no current ,
a3 will show 1A and
a will show 2A(a1+a3).