9. An automobile's oxygen sensor output needs to be checked. Technician A uses a digital
voltmeter to check this sensor's output.
Technician B uses an analog ohmmeter to
check this sensor's output. Who is right?
(A) A only.
(B) B only.
(C) Both A and B.
(D) Neither A nor B.

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Water at 55c flows across a flat plate whose surface temperature is held constant at 95c. if the temperature gradient at the plate's surface for a given value of x is 18 c/mm, find a) local heat transfer coefficient. b) heat flux

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.