Machine Design
If threads on a bolt are left hand, threads on nut will be

Right hand with fine pitch
Right hand with same pitch
Left hand with same pitch
Could be left or right hand

ANSWER DOWNLOAD EXAMIANS APP

Machine Design
In replacing the V-belts, a complete set of new belts is used instead of replacing a single damaged belt because

Belts are available in sets
The new belt will carry more than its share and result in short life
Only one belt cannot be fitted with other used belts
New and old belts will cause vibrations

ANSWER DOWNLOAD EXAMIANS APP