A long cylindrical wire (radius = 2.0 cm) carries a current of 40 A that is uniformly distributed over a cross section of the wire. What is the magnitude of the magnetic field at a point which is 1.5 cm from the axis of the wire?
a. 0.53 mT
b. 28 mT
c. 0.30 mT
d. 40 mT
e. 1.9 mT
c
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One mole of helium gas expands adiabatically from 2 atm pressure to 1 atm pressure. If the original temperature of the gas is 20°C, what is the final temperature of the gas? (? = 1.67)
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a. It decreases. b. It remains the same. c. It increases. d. More information is needed to make this conclusion.
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