Portage Phys 165 Module 7 Exam With Correct Answers

Portage Phys 165 Module 7 Exam With
Correct Answers.




True or False: Atoms are made up of protons, neutrons, and electrons. Protons carry a positive charge,
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electrons carry a negative charge, and neutrons do not carry any charge.CORRECT ANSWERS✔✔True
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True or False: When something acquires a net charge, it can be either the protons or the electrons that move,
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but not the neutrons.CORRECT ANSWERS✔✔False
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What is the unit of charge?CORRECT ANSWERS✔✔Coulombs
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True or False: Two identical, conductive spheres have net charges on them. Sphere A has a net charge of +2.50
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mC and sphere B has a net charge of +3.81 mC. The two spheres are released in space and move only because
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of the electrostatic forces between them. When released, the two spheres should move away from each
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other.CORRECT ANSWERS✔✔True
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What is the name of a device that stores electric charge?CORRECT ANSWERS✔✔Capacitor
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, A variable capacitor has too much capacitance. Which of the following changes would NOT reduce the
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capacitance of this capacitor?CORRECT ANSWERS✔✔Switch the dielectric for a new one that has a larger
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dielectric constant
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When you rub a balloon on your hair, it scrapes electrons off your hair and deposits them onto the balloon.
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The balloon becomes negatively charged, and your hair becomes positively charged. What is the name of this
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process of charging an object?CORRECT ANSWERS✔✔Fricton
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True or False: The Fundamental Law of Electrostatics states that opposite charges repel each other while like
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charges attract each other.CORRECT ANSWERS✔✔False. Opposite Charges Attract/Like Charges Repel
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When a lightning bolt strikes a tree, -8.42 C of charge is transferred from the ground up to the clouds. How
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many electrons were transferred to the clouds from the tree?CORRECT ANSWERS✔✔Take the charge;
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convert using (1e-/-1.60x10^-19C)
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Answer in electrons J J




An atom of Potassium-40 has 19 protons, 20 neutrons, and 18 electrons. What is the sign and magnitude of
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the net charge of this atom in Coulombs?CORRECT ANSWERS✔✔19-18 = +1e- (1.60x10^-19/1e-) =
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1.60x10^-19
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Answer in C J J




A purple metal nut has been given a net charge of + 6325 nC, and an orange metal nut has been given a net
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charge of - 3614 nC. Answer the following questions:
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a. What is the magnitude of the electrostatic force between these two nuts if they are separated by 25 cm?
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b. Is the force attractive or repulsive?
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c. Which nut has the largest electrostatic force acting on it?CORRECT ANSWERS✔✔a) F= k*q1*q2/r^2
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where k= 9.0x10^9Nm^2/kg^2
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Answer in Newtons J J J




b) Force is negative so it's attractive
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