Machine Design
A woodruff key is

A tapered key with head at one end
Fitted in pairs at right angles
All of these
Capable of tilting in a recess milled out in the shaft

ANSWER DOWNLOAD EXAMIANS APP

Machine Design
A fast and loose pulley drive is used when

Shafts are arranged at right angles and rotate in one definite direction
Shafts are arranged parallel and rotate in the same directions
Shafts are arranged parallel and rotate in the opposite directions
Driven shaft is to be started or stopped whenever desired without interfering with the driving shaft

ANSWER DOWNLOAD EXAMIANS APP