If two protons are moved 3 times closer together, the electrical force between them is what factor of the original force?
[Ques. 2] A layer of ethyl alcohol (n = 1.361) is on top of water (n = 1.333). To the nearest degree, at what angle relative to the normal to the interface of the two liquids is light totally reflected?
a. 78
b. 88
c. 68
d. 49
e. the critical angle is undefined
[Ques. 3] A star of magnitude 1 appears _______________ times brighter than a star of magnitude 2.
a. 5.21
b. 3.14
c. 10
d. 2.51
[Ques. 4] If two protons are moved 3 times farther apart, the electrical force between them is what factor of the original force?
[Ques. 5] A diver shines an underwater searchlight at the surface of a pond (n = 1.33). At what angle (relative to the surface) will the light be totally reflected?
a. 47.3
b. 41.2
c. 51.1
d. 58.7
e. 49.8
[Ques. 6] In a star, the condition of balance between the inward force of gravity and the outward force of thermal and radiation pressure is known as _______________ equilibrium.
a. hydrostatic
b. thermal
c. photostatic
d. magnetostatic
[Ques. 7] An insulator has a positive electric charge of 2.4 10 -17 C. How many electrons were added or removed?
[Ques. 8] Light strikes a diamond (n = 2.42) immersed in glycerin (n = 1.473) at an angle of 60 relative to the normal to the surface. What is the angle of refraction?
a. 20
b. 60
c. 32
d. 64
e. 15
[Ques. 9] One ______________ is the distance to a star when the star exhibits a parallax of one second of arc.
a. parsec
b. light-year
c. astronomical unit
d. million miles
[Ques. 10] Three resistors, 10 , 20 , and 30 , are wired in series and connected to a 120-V battery. How much current flows in the circuit?
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