Technician A says that ultraviolet light is bright, and very hot. Technician B says that ear protection does not need to be used when welding. Who is correct? a. Technician A only
b. Technician B only
c. Both Technicians A and B
d. Neither Technician A nor B

Draw the engineering stress-strain curve for (a) bcc; (b) fcc metals and mark important points.

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.

The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object