20. In a port fuel-injected engine, shorter runners yield A. minimum high-RPM power.
B. increased low-RPM power.
C. minimum low-RPM power.
D. increased high-RPM power.

Thermal stresses are developed in a metal when its a) initial temperature is changed b) final temperature is changed c) density is changed d) thermal deformation is prevented e) expansion is prevented f) contraction is prevented

Water at the rate of 1 kg/s is forced through a tube with a 2.5 cm inner diameter. the inlet water temperature is 15°c, and the outlet water temperature is 50°c. the tube wall temperature is 14°c higher than the local water temperature all along the length of the tube. what is the length of the tube?

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false