What is thought to be at the center of most galaxies?
A. an open cluster
B. a massive black hole
C. a regularly exploding nova
D. an unusually large and bright main sequence star
E. a globular cluster
Answer: B
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A 120-V rms voltage at 1000 Hz is applied to a series RLC circuit with an equal value of inductive and capacitive reactance and a 200-? resistance. What is the impedance of this circuit?
A) 240 ? B) 120 ? C) 100 ? D) 0 ? E) 200 ?
The energies of two photons you might detect emitted by hydrogen atoms are 10.2 and 2.1 eV. Which photon has the longest wavelength?
A) the 10 eV photon B) the 2.1 eV photon C) They both have the same wavelength.
An object of mass m and moment of inertia I has rotational kinetic energy KER. Its angular momentum is:
a. 0.5 I/m. c. (2 mKER)1/2. b. (2 IKER)1/2. d. not given.
What is the de Broglie wavelength of a ball of mass 200. g moving with a speed of 30. m/s?
A) 1.1 × 10-34 m B) 4.5 × 10-28 m C) 6.67 × 10-28 m D) 2.2 × 10-34 m E) 6.67 × 10-31 m