PART I · SHORT RESPONSE第一部分 · 短答题AP-style MCQ + ON/BC short answer · 19 marksAP 风格选择题 + 安/卑省考短答 · 共 19 分
Section A · Short ResponseA 部分 · 短答题
Mix of multiple-choice and short-answer items. For MCQs, circle the letter; show enough work in the margin that a marker could verify. For short-answer items, state units in every answer and the direction where a vector is asked. Take $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$ and the elementary charge $e = 1.6\times10^{-19}\ \text{C}$. Calculator permitted on Q4-Q5.本节包含选择题与短答题。选择题请圈出字母答案，并在空白处写下足以让阅卷人核对的过程。短答题每道都要写出单位，求矢量时还须写出方向。取 $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$，基本电荷 $e = 1.6\times10^{-19}\ \text{C}$。Q4-Q5 可用计算器。
Q1EASY易🇺🇸 US美AP-style MCQAP 风格选择题§1 Magnetic field lines磁场线 · HS-PS2-5[3 marks][3 分]
In the space outside a bar magnet, magnetic field lines are drawn so that they:在条形磁铁外部空间，磁场线的画法满足：
(A)exit the south pole and enter the north pole从南极出发，进入北极
(B)exit the north pole and enter the south pole从北极出发，进入南极
(C)begin on the north pole and end in empty space起始于北极，终止于空旷处
(D)cross one another midway between the poles在两极中间彼此相交
A proton moves at $2.0\times10^6$ m/s perpendicular to a uniform $0.30$ T magnetic field. What is the magnitude of the magnetic force on it? ($e = 1.6\times10^{-19}$ C)一个质子以 $2.0\times10^6$ m/s 垂直于 $0.30$ T 匀强磁场运动。它所受磁力的大小是多少？（$e = 1.6\times10^{-19}$ C）
(A) $9.6\times10^{-14}\ \text{N}$
(B) $4.8\times10^{-20}\ \text{N}$
(C) $6.0\times10^{5}\ \text{N}$
(D) $0\ \text{N}$
Q3EASY易🇨🇦 ON安ON Provincial-style安大略省考风格§3 Force on a wire导线受力 · SPH3U F2[4 marks][4 分]
A straight horizontal wire of length $0.50$ m carries a current of $6.0$ A directed north. It lies in a uniform $0.40$ T magnetic field directed vertically upward.一根长 $0.50$ m 的水平直导线通有 $6.0$ A 向北的电流，置于竖直向上的 $0.40$ T 匀强磁场中。
(a)Compute the magnitude of the force on the wire, with units.计算导线所受力的大小，并写出单位。[2]
(b)Use the right-hand rule to state the direction of the force.用右手定则写出力的方向。[1]
(c)State what happens to the force if the current is reversed.写出电流反向时力会如何变化。[1]
Q4MEDIUM中🇺🇸 US美AP-style MCQAP 风格选择题§4 Field of a straight wire直导线的磁场 · HS-PS2-5[4 marks][4 分]
A long straight wire carries a current of $10$ A. What is the magnitude of the magnetic field at a perpendicular distance of $5.0$ cm from the wire? ($\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$)一根长直导线通有 $10$ A 电流。距导线垂直距离 $5.0$ cm 处的磁场大小是多少？（$\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$）
An electron travels horizontally east at $3.0\times10^5$ m/s through a uniform magnetic field that points vertically upward.一个电子以 $3.0\times10^5$ m/s 水平向东穿过一个竖直向上的匀强磁场。
(a)Use the right-hand rule (remembering the electron is negative) to state the direction of the magnetic force on the electron.用右手定则（注意电子带负电）写出电子所受磁力的方向。[2]
(b)Explain why the magnetic force does no work on the electron, and describe the resulting path.解释磁力为何对电子不做功，并描述其运动路径。[2]
(c)State what the magnetic force would be if the electron instead moved straight up (parallel to the field).写出若电子改为竖直向上（与磁场平行）运动时所受的磁力。[1]
PART II · EXTENDED RESPONSE第二部分 · 简答题AP-feeder FRQ + honors · 32 marksAP 衔接简答题 + 荣誉级 · 共 32 分
Section B · Extended ResponseB 部分 · 简答题
Show every step of reasoning. State the formula used before substituting values, and state units in every final answer. Use $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$, proton mass $m_p = 1.67\times10^{-27}$ kg, $e = 1.6\times10^{-19}$ C. The honors items (Q7-Q9) use quantitative Faraday/Lenz analysis, which is assessed only qualitatively under US NGSS. Calculator permitted throughout Part II.每一步推理都要写出。代入数值前先写出所用公式，每个最终答案都要写单位。取 $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$，质子质量 $m_p = 1.67\times10^{-27}$ kg，$e = 1.6\times10^{-19}$ C。荣誉级题（Q7-Q9）使用定量的法拉第/楞次分析，在 US NGSS 中仅作定性考查。第二部分全程可用计算器。
Q6MEDIUM中🇺🇸 US美AP-feeder FRQAP 衔接简答题§2 Charge in a field (circular motion)磁场中电荷（圆周运动） · HS-PS2-5[8 marks][8 分]
A proton ($m_p = 1.67\times10^{-27}$ kg, $q = 1.6\times10^{-19}$ C) enters a uniform $0.20$ T magnetic field, moving at $5.0\times10^5$ m/s perpendicular to the field.一个质子（$m_p = 1.67\times10^{-27}$ kg，$q = 1.6\times10^{-19}$ C）以 $5.0\times10^5$ m/s 垂直于磁场进入一个 $0.20$ T 的匀强磁场。
(a)Find the magnitude of the magnetic force on the proton.求质子所受磁力的大小。[2]
(b)The force keeps the proton in a circle. Find the radius of the circular path using $r = mv/(qB)$.该力使质子做圆周运动。用 $r = mv/(qB)$ 求圆周路径的半径。[2]
(c)Find the period of one orbit using $T = 2\pi m/(qB)$.用 $T = 2\pi m/(qB)$ 求绕行一周的周期。[2]
(d)State how the radius and the period each change if the field strength $B$ is doubled. Justify each answer.写出当磁场强度 $B$ 加倍时，半径与周期各自如何变化，并说明理由。[2]
A flat coil of $N = 200$ turns has an area of $0.015\ \text{m}^2$ and lies perpendicular to a magnetic field. The field is reduced steadily from $0.80$ T to $0.20$ T in $0.50$ s. The coil has a total resistance of $10\ \Omega$.一个 $N = 200$ 匝的扁平线圈面积为 $0.015\ \text{m}^2$，平面垂直于磁场。磁场在 $0.50$ s 内从 $0.80$ T 均匀减小到 $0.20$ T。线圈总电阻为 $10\ \Omega$。
(a)Find the change in magnetic flux through one turn of the coil.求穿过线圈一匝的磁通量变化量。[2]
(b)Find the magnitude of the induced EMF using $|\varepsilon| = N|\Delta\Phi/\Delta t|$.用 $|\varepsilon| = N|\Delta\Phi/\Delta t|$ 求感应电动势的大小。[3]
(c)Find the induced current in the coil.求线圈中的感应电流。[2]
(d)State one change to the setup that would double the induced EMF.写出一种能使感应电动势加倍的改动。[1]
The north pole of a bar magnet is pushed toward the face of a circular coil, so the magnetic flux through the coil increases.一根条形磁铁的北极推向圆形线圈的正面，使穿过线圈的磁通量增大。
(a)State Lenz's law and use it to determine the direction (as seen from the magnet) of the induced current in the coil.陈述楞次定律，并用它判断（从磁铁侧观察）线圈中感应电流的方向。[2]
(b)State which magnetic pole the coil presents to the approaching magnet, and whether the magnet is attracted or repelled.写出线圈向靠近的磁铁呈现哪个磁极，以及磁铁是被吸引还是被排斥。[2]
(c)Explain how this result is required by conservation of energy.解释这一结果为何是能量守恒所要求的。[2]
(d)A solid aluminium plate is then swung through the gap of a strong magnet and slows down noticeably. Name this effect and explain it using Lenz's law.随后将一块实心铝板摆过强磁铁的间隙，铝板明显减速。说出这一效应的名称，并用楞次定律解释。[2]
An AC generator has a coil of $N = 100$ turns, each of area $A = 0.020\ \text{m}^2$, rotating in a uniform $B = 0.25$ T magnetic field at a frequency of $60$ Hz. The peak EMF of such a generator is $\varepsilon_0 = NBA\omega$, where $\omega = 2\pi f$.一台交流发电机的线圈有 $N = 100$ 匝，每匝面积 $A = 0.020\ \text{m}^2$，在 $B = 0.25$ T 的匀强磁场中以 $60$ Hz 的频率旋转。这种发电机的峰值电动势为 $\varepsilon_0 = NBA\omega$，其中 $\omega = 2\pi f$。
(a)Find the angular frequency $\omega$ of the rotating coil.求旋转线圈的角频率 $\omega$。[2]
(b)Find the peak EMF $\varepsilon_0$ produced by the generator.求发电机产生的峰值电动势 $\varepsilon_0$。[3]
(c)Explain why the EMF is zero at the instant the coil plane is perpendicular to $\vec B$ (flux maximum), and maximum when the plane is parallel to $\vec B$ (flux zero).解释为何当线圈平面垂直于 $\vec B$（磁通量最大）时电动势为零，而当平面平行于 $\vec B$（磁通量为零）时电动势最大。[2]
(d)State one change that would double the peak EMF.写出一种能使峰值电动势加倍的改动。[1]
PART III · MODELING / APPLIED第三部分 · 建模与应用AB Diploma + Universal · 30 marks阿省毕业考 + 通用题型 · 共 30 分
Section C · Modeling and ApplicationsC 部分 · 建模与应用
Define symbols (with units) at the start of each question. State the formula used before substituting. Take $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$ (use $\pi \approx 3.14$ where needed). Conclude each question with a one-sentence answer in context. Calculator permitted throughout Part III.每题开始时定义符号（含单位）。代入数值前先写出所用公式。取 $\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$（需要时取 $\pi \approx 3.14$）。每题以一句结合情境的完整句子作答。第三部分全程可用计算器。
An engineer winds a solenoid of $N = 500$ turns over a length of $L = 0.50$ m and passes a current of $I = 4.0$ A through it. ($\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$, use $\pi \approx 3.14$)一位工程师在 $L = 0.50$ m 长度内绕制 $N = 500$ 匝的螺线管，并通入 $I = 4.0$ A 的电流。（$\mu_0 = 4\pi\times10^{-7}\ \text{T}\cdot\text{m/A}$，取 $\pi \approx 3.14$）
(a)Find the number of turns per metre, $n$.求每米匝数 $n$。[2]
(b)Find the magnetic field strength inside the solenoid using $B = \mu_0 n I$.用 $B = \mu_0 n I$ 求螺线管内部的磁场强度。[3]
(c)The current is then tripled and the number of turns per metre is doubled. By what factor does the interior field change?随后将电流增至三倍、每米匝数增至两倍。内部磁场变为原来的几倍？[2]
(d)State one advantage of this electromagnet over a permanent magnet for industrial use.写出在工业应用中，这种电磁铁相对于永磁体的一个优点。[2]
A substation transformer has a primary of $N_p = 300$ turns supplied at $V_p = 120$ V, and a secondary of $N_s = 1500$ turns. The primary current is $I_p = 8.0$ A. Treat the transformer as ideal.一台变电站变压器初级有 $N_p = 300$ 匝，输入电压 $V_p = 120$ V，次级有 $N_s = 1500$ 匝。初级电流 $I_p = 8.0$ A。视为理想变压器。
(a)Find the secondary voltage $V_s$ and state whether this is a step-up or step-down transformer.求次级电压 $V_s$，并说明这是升压还是降压变压器。[3]
(b)Find the secondary current $I_s$.求次级电流 $I_s$。[2]
(c)Verify that input power equals output power.验证输入功率等于输出功率。[2]
(d)Explain why transformers must operate on alternating current, not direct current.解释变压器为何必须使用交流电而非直流电工作。[2]
Q12HARD难🇺🇸 US美AP-feeder FRQAP 衔接简答题§3 + §7 Motor force & grid transmission电动机受力与电网输电 · HS-PS2-5[12 marks][12 分]
A simple motor coil has one straight side of length $0.20$ m carrying a current of $4.0$ A. This side sits perpendicular to a uniform $0.50$ T field. The same plant that runs the motor must also send $P = 120$ kW of power down a transmission line of total resistance $R = 0.20\ \Omega$.一台简单电动机的线圈有一条长 $0.20$ m 的直边，通有 $4.0$ A 电流。该边垂直于 $0.50$ T 的匀强磁场。驱动该电动机的同一发电厂还须沿总电阻 $R = 0.20\ \Omega$ 的输电线输送 $P = 120$ kW 的功率。
(a)Find the magnetic force on that side of the coil using $F = BIL$.用 $F = BIL$ 求线圈该边所受磁力。[2]
(b)Explain how the forces on the two opposite sides of the coil combine to produce a turning effect (torque) that spins the motor.解释线圈两条对边所受的力如何合成产生使电动机旋转的转动效应（力矩）。[2]
(c)Find the line current and the power lost in the line if the power is transmitted at $240$ V, then again if it is transmitted at $4800$ V. Use $I = P/V$ and $P_{\text{loss}} = I^2 R$.分别求以 $240$ V 和以 $4800$ V 输电时的线路电流和线路损耗功率。使用 $I = P/V$ 和 $P_{\text{loss}} = I^2 R$。[5]
(d)By what factor do the line losses drop, and explain how a transformer makes high-voltage transmission possible.线路损耗下降为原来的几分之一？并解释变压器如何使高压输电成为可能。[3]
🇺🇸 US NGSS美国 NGSSHS-PS2-5
🇨🇦 Ontario安大略SPH3U Strand F · SPH4U Strand D · F2 · F3
🇨🇦 British Columbia不列颠哥伦比亚Physics 12: magnetic fields, magnetic force, Faraday's & Lenz's laws物理 12：磁场、磁力、法拉第与楞次定律
🇨🇦 Alberta阿尔伯塔Physics 30 Unit B · 30-B3.5k · 30-B3.8k · 30-B3.9k
Full Syllabus Map lives in ../Study Guides/Unit_10_Magnetism_and_Electromagnetic_Induction.html. Note: US NGSS HS-PS2-5 assesses electromagnetic induction qualitatively only; the quantitative Faraday and Lenz items (Q7-Q9) carry the Honors flag for the NGSS track but are core for ON SPH3U/SPH4U / BC Physics 12 / AB Physics 30.完整大纲对照表见 ../Study Guides/Unit_10_Magnetism_and_Electromagnetic_Induction.html。注：US NGSS HS-PS2-5 仅定性考查电磁感应；定量的法拉第与楞次题（Q7-Q9）在 NGSS 轨道上标注荣誉级，但为安大略 SPH3U/SPH4U / 卑诗物理 12 / 阿省物理 30 的核心内容。