Two technicians are discussing brake light bulbs. Technician A says that a two-filament bulb uses the second
filament as a back-up if the first filament burns out. Technician B says that two-filament bulbs have different
wattage filaments. Who is correct?
Select one
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A nor B

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]