Physics — Semester B
Free Practice · 10 Questions · 20 min
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Question 1 of 10
TEKS 1Medium Calc Word Diagram

The diagram shows two point charges. Charge A has +4 μC and charge B has +2 μC. They are separated by 0.10 m. What is the direction of the force on charge B due to charge A?

A+4 μCB+2 μC0.10 m
APerpendicular to the line AB
BToward A (attractive)
CZero force
DAway from A (repulsive)
Explanation
📌 Both charges are positive (like charges). Like charges REPEL. So force on B points AWAY from A. Magnitudes are given: F = kq_A q_B/d² = (8.99×10⁹)(4×10⁻⁶)(2×10⁻⁶)/(0.10)² = 7.19 N, but the question asks direction only. Distractor A: opposite direction; C: force is nonzero; D: force is along line, not perpendicular.
Question 2 of 10
TEKS 2Easy Word

A 12 V battery is connected across a 4 Ω resistor. What is the current through the resistor?

12 V battery across 4 Ω resistor — current+−V = 12 VR = 4 ΩIFind the current I through the resistor.
A48 A
B16 A
C3.0 A
D0.33 A
Explanation
📌 Ohm's law: I = V/R = 12/4 = 3.0 A. Distractor A: reciprocal (R/V); C: multiplied V × R; D: added V + R.
Question 3 of 10
TEKS 2Medium Calc Word Diagram

In the circuit shown, a 12 V battery drives current through two resistors in series: R₁ = 4 Ω and R₂ = 8 Ω. What is the current through R₁?

12 VR14 ΩR28 ΩI
A3.0 A
B1.5 A
C1.0 A
D0.5 A
Explanation
📌 Series: R_total = 4 + 8 = 12 Ω. Current is the same everywhere: I = V/R = 12/12 = 1.0 A. Distractor A: only used R₂; C: split difference; D: forgot to add resistors (used just R₁: 12/4 = 3).
Question 4 of 10
TEKS 3Hard Calc Word Diagram

The diagram shows a straight wire carrying current I to the right, placed in a magnetic field B pointing INTO the page. What is the direction of the magnetic force on the wire?

Straight wire in uniform magnetic field B (into page)××××××××××××××××××××B (into page)Iwire carries current I to the right
ADownward (toward bottom of page)
BSame direction as B (into page)
CUpward (out of the wire, toward top of page)
DSame direction as I (along the wire)
Explanation
📌 Right-hand rule for F = IL × B: fingers point right (direction of I), curl into the page (direction of B), thumb points UP. Force is upward. Distractor B: opposite; C: force is always perpendicular to B; D: force is always perpendicular to I.
Question 5 of 10
TEKS 2Easy Word

The SI unit of electric current is:

AVolt
BWatt
CAmpere
DCoulomb
Explanation
📌 The ampere (A) is the SI unit of current. 1 A = 1 C/s. Distractor A: coulomb is charge; C: volt is potential; D: watt is power.
Question 6 of 10
TEKS 1Easy Word

Which of the following is a good conductor of electricity?

ACopper
BWood
CRubber
DGlass
Explanation
📌 Metals are conductors because their electrons can move freely. Copper is one of the most-used conductors. Wood, rubber, and glass are insulators.
Question 7 of 10
TEKS 5Medium Calc Word Diagram

The diagram shows energy levels of an atom. An electron transitions from level n = 3 to level n = 1. What happens?

Electron transition n = 3 → n = 1E3E2E1n = 3n = 2n = 1e-
AThe atom absorbs a photon of energy hf
BNothing happens
CThe atom emits a photon with energy equal to E₃ − E₁
DThe atom loses one proton
Explanation
📌 When an electron drops from a higher energy level to a lower one, the atom emits a photon whose energy = E_higher − E_lower. Frequency of the emitted photon is set by hf = ΔE. This is the origin of emission spectra. Distractor A: absorption is the reverse process; C: protons are in the nucleus, not affected by electron transitions; D: emission happens.
Question 8 of 10
TEKS 1Medium Calc Word Diagram

The diagram shows electric field lines around two point charges. What is the sign of each charge?

AB
AA is −, B is +
BA is +, B is −
CA is +, B is +
DA is −, B is −
Explanation
📌 Field lines EMERGE from positive charges and CONVERGE into negative charges. In the diagram, arrows point OUT of A (so A is positive) and INTO B (so B is negative). Distractor A: both would show outward arrows; C: reversed; D: both would show inward arrows.
Question 9 of 10
TEKS 4Hard Calc Word Diagram

The ray diagram shows an object placed farther than 2f from a converging (convex) lens. What is TRUE of the image?

Converging lens · object at distance 3F from the lens2FFF′2F′lensobjectd0 = 3F
AReal, upright, and enlarged
BVirtual, upright, and enlarged
CReal, inverted, and reduced
DVirtual, inverted, and same size
Explanation
📌 Object beyond 2f of a converging lens: image is on the OPPOSITE side (real), inverted (flipped), and reduced (smaller than object). This is how a camera lens works. Distractor B: describes a magnifying glass (object within f); C: converging lens never produces upright real image; D: nonsense combination.
Question 10 of 10
TEKS 1Easy Word

Two objects that carry positive charges are placed near each other. What is the force between them?

Two positive charges placed near each other++FFBoth charges have the same sign — what is the direction of the force?
AAttractive
BDepends on distance only
CRepulsive
DZero
Explanation
📌 Like charges repel; unlike charges attract. Two positives push apart.

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