longitudinal movement of rail
lateral movement of rail
vertical movement of rail
difference in level of two rails
bridges and approaches
joints
both [a] and [b]
none of the above
only (i)
(i)and(ii)
(ii) and (iii)
(i), (ii) and (iii)
10°
16°
30°
40°
on curves
on straight track
when two different rail sections are required to be joined