(a) Prevent sparking across the gap between the points

(b) Cause more rapid break of the primary current, giving a higher voltage in the secondary circuit

Both (a) and (b)

None of the above

At the same speed and in the same direction

At the same speed but in opposite direction

At different speeds and in the same direction

At different speeds in the opposite direction

Sub-sonic flow

Sonic flow

Super-sonic flow

Hyper-sonic flow

Carnot cycle

Stirling cycle

Otto cycle

None of these

Low carbon steel

Medium carbon steel

High carbon steel

Alloy steel