Practice Final Exam

Practice Final Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) What is the longest wavelength in the Lyman Series? A) 91.20 nm B) 365 nm C) 45.60 nm D) 240.1 nm E) 121.5 nm
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2) What is the energy of the photon emitted when an electron drops from the n=20 state to the n =7 state in a hydrogen atom? A) 0.303 eV B) 0.244 eV C) 0.264eV D) 0.283 eV
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3) In a hydrogen atom, a given electron has ℓ
=7. How many possible values can m1 have? A) 7 B) 98 C) 15 D) 6
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4) Light shines through atomic hydrogen gas that was initially in its ground state. You observe that after awhile much of the hydrogen gas has been excited to its n = 5 state. What wavelength of light

What is the magnitude of the second charge? (k = 1/4πε0 = 9.0 × 109 N ∙ m2/C2) A) 0.025 C B) 25 nC C) 25 C D) 10 nC E) 1.0 C
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6) As shown in the figure, three charges are at corners of a rectangle. The charge in the bottom right corner is Q = - 90 nC, and all the other quantities are accurate to two significant figures. What is the magnitude of the net electrical force on Q due to the other two charges? (k = 1/4πε0 = 9.0 × 109 N ∙ m2/C2)
A) 7.1 × 10-2 N B) 3.8 × 10-2 N C) 2.8 × 10-2 N D) 5.3 × 10-2 N
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7) Two tiny particles having charges +20.0μC and -8.00μC are separated by a distance of 20.0 cm. What are the magnitude and direction of electric field midway between these two charges? (k = 1/4 πε0 = 9.0 × 109 N ∙ m2/C2) A) 25.2 × 106 N/C directed towards the negative charge B) 25.2 × 105 N/C directed towards the negative charge C) 25.2 × 104 N/C directed towards the negative charge D) 25.2 × 105 N/C directed towards the positive charge E) 25.2 × 106 N/C directed towards the positive charge
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8) A +4.0-μC and a -4.0-μC point charge are placed as shown in the figure. What is the potential difference between points A and B? (k = 1/4πε0 = 9.0 × 109 N ∙ m2/C2)
A) 96 V B) 48 V C) 96 kV D) 48 kV E) 0

How many electrons flow through the wire in 1.0 min? (e = 1.60 × 10-19 C) A) 2.5 × 1019 B) 3.5 × 1019 C) 4.5 × 1019 D) 1.5 × 1019
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10) What is the resistance of 1.0 m of a solid cylindrical metal cable having a diameter of 0.40 inches and a resistivity of 1.68 × 10-8 Ω ∙ m? A) 0.00021 Ω B) 0.0021 Ω C) 0.00012 Ω D) 0.0012 Ω
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11) If V = 20 V and the battery is ideal, what is the current through R3 in the figure?
A) 0.050 A B) 0.20 A C) 4.0 A D) 1.0 A
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12) A 5.0-μF and a 12.0-μF capacitor are connected in series, and the series arrangement is connected in parallel to a 29.0-μF capacitor. How much capacitance would a single capacitor need to replace this combination of three capacitors? A) 13 μF B) 38 μF C) 33 μF D) 16 μF 12)
13) An electron moves with a speed of 5.0 × 104 m/s perpendicular to a uniform magnetic field of magnitude 0.20 T. What is the magnitude of the magnetic force on the electron? (e = 1.60 × 10-19 C) A) 4.4 × 10-14 N B) zero C) 2.6 × 10-24 N D) 5 × 10-20 N E) 1.6 × 10-15 N
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