A thin copper rod 1.0 m long has a mass of 0.050 kg and is in a magnetic field of 0.10 T. What minimum current in the rod is needed in order for the magnetic force to balance the weight of the rod?
A) 9.8 A B) 2.5 A C) 1.2 A D) 4.9 A
D
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Which of the following statements about Saturn's moon Titan is not true?
A) It rains liquid methane and ethane. B) Its atmosphere contains abundant oxygen. C) Its temperature is too cold for liquid water to exist on its surface. D) Its surface is hidden from view by a thick atmosphere. E) It orbits Saturn.
A resistor and an ideal inductor are connected in series to an ideal battery having a constant terminal voltage V0. At the moment contact is made with the battery,
(a) the voltage across the resistor is A) V0. B) V0/e. C) V0/2. D) zero. (b) the voltage across the inductor is A) V0. B) V0/e. C) V0/2. D) zero. What will be an ideal response?
A star of spectral type B with a mass of 10 times the mass of the Sun lives approximately how long on the main sequence?
A) 10 billion years B) 10 million years C) 1,000 years D) 10,000 years E) 1 billion years
In 1960, the scientist named __________ proposed the concept of seafloor spreading
a. Andrija Mohorovicic b. Harry Hess c. Alfred Wegener d. None of the above