Theory of Machine
The frictional torque transmitted in a flat collar bearing, considering uniform wear, is (where r₁ and r₂ = External and internal radii of collar respectively)

(2/3) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]
(2/3) μ W (r₁ + r₂)
(1/2) μ W (r₁ + r₂)
(1/2) μ W [(r₁³ - r₂³)/(r₁² - r₂²)]

ANSWER DOWNLOAD EXAMIANS APP

Theory of Machine
In a steam engine, the earlier cut-off with a simple slide valve may be obtained by increasing the steam lap and the angle of advance of the eccentric but keeping constant the travel and lead of the valve, this method will

Cause withdrawing or throttling of steam
Reduce maximum opening of port to steam
All of the listed here
Reduce length of effective stroke of piston

ANSWER DOWNLOAD EXAMIANS APP