Because of the period-luminosity relation for Cepheids and RR Lyrae variable stars, astronomers are able to _____
a. determine the relationship between the period of pulses and luminosity
b. measure the mass of a star
c. calculate a star's diameter
d. determine the chemical composition of a Type I Cepheid
e. narrow their study to eclipsing binary stars only
a
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Interstellar reddening of starlight occurs because the interstellar dust preferentially ________ the blue light
Fill in the blank(s) with correct word
At what frequency will the Inductive Reactance of 44. mH be equal to the Capacitive Reactance of a 27. pF capacitor?
What will be an ideal response?
Two uniform rods, each of length 2.0 m, are bent to form semicircles. One rod has a charger per unit lent of 1.5 nC/m, and the other has a charge per unit length of -1.5 nC/m. The semicircles are joined to make a circle. What is the magnitude of the electric field at the center of the circle?
A. 42 N/C B. 84 N/C C. 34 N/C D. 68 N/C E. 0
When unequal resistors are connected in parallel in a circuit,
A) the same current always runs through each resistor. B) the potential drop is always the same across each resistor. C) the largest resistance has the largest current through it. D) the power generated in each resistor is the same.