Engineering Mechanics
Angle of friction is the

Angle between normal reaction and the resultant of normal reaction and the limiting friction
Ratio of limiting friction and normal reaction
The ratio of minimum friction force to the friction force acting when the body is just about to move
The ratio of minimum friction force to friction force acting when the body is in motion

ANSWER DOWNLOAD EXAMIANS APP

Engineering Mechanics
One joule means that

Work is done by a force of 1 dyne when it displaces a body through 1 cm
Work is done by a force of 1 kg when it displaces a body through 1 m
Work is done by a force of 1 N when it displaces a body through 1 m
Work is done by a force of 1 g when it displaces a body through 1 cm

ANSWER DOWNLOAD EXAMIANS APP