A long hollow cylindrical conductor (inner radius = 2.0 mm, outer radius = 4.0 mm) carries a current of 12 A distributed uniformly across its cross section. A long wire which is coaxial with the cylinder carries an equal current in the same direction. What is the magnitude of the magnetic field 3.0 mm from the axis?
a. 1.1 mT
b. 1.4 mT
c. 1.7 mT
d. 2.0 mT
e. 0.2 mT
a
You might also like to view...
An attractive method of energy conservation in industrial settings is to utilize waste heat from largescale power generating equipment. In one such scheme, the exhaust gases from the diesel engine of an industrial power generator are channeled through a cross- flow, compact, waste-heat recovery boiler to produce process steam. In one such heat exchanger, a finned tube bundle is configured with tubes of 2.5 cm outer diameter that are arranged in a staggered equilateral- triangular array with tube center-to-center pitch of 7.5 cm. Engine exhaust gas (thermal properties of which are taken to be the same as those for air) at 400°C is in cross-flow over the tube bank with a free stream velocity of 2.0 m/s. In order to enhance the gas-side convective heat transfer, the tubes have thin circular
fins on their outer surface and the finned surface extension ratio ?=1.15. Due to the steam generation process inside the tubes, their outer surface temperature is 175°C. If there are 10 rows of tubes in the flow direction (NL = 10), calculate the average heat transfer coefficient and pressure drop for the gas flow stream.
GIVEN
FIND
The average heat transfer coefficient (c h) and pressure drop in gas flow stream.
ASSUMPTIONS
Steady state
Tube wall temperature is uniform and constant
SKETCH
PROPERTIES AND CONSTANTS
A temperature difference of 9.0 Celsius degrees is equal to a Fahrenheit temperature difference of
A. 5.0 Fahrenheit degrees. B. 9.0 Fahrenheit degrees. C. 16 Fahrenheit degrees. D. 37 Fahrenheit degrees. E. 41 Fahrenheit degrees.
The type of smog that forms in Los Angeles is called ______________ smog
Fill in the blank(s) with correct word
In semi-crystalline polymers, there is a spike in the specific heat when the crystallites start to _____________.
Fill in the blank(s) with the appropriate word(s).