Name: single phase transformer testing
Uploaded: 2023-04-30T06:42:08.000Z
Duration: 10 min 50 s
Channel: JoVE

K12 Standards

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

High School

Physics

motion-and-stability-forces-and-interactions

Motion and Stability: Forces and Interactions

P-PS2-6.

Single Phase Transformers

1. 直流测试
<ol><li>打开工作台上可用的低压直流电源。</li>
	<li>将其电压输出设置为 0 V, 并将当前限制设置为0.8。</li>
	<li>双检查电路连接, 然后将电源输出连接到主侧绕组 (IN1 和 IN2)。离开二次侧绕组 (OUT1 和 OUT2) 打开。</li>
	<li>打开电源, 并稍微增加电压, 直到达到当前限制。请注意, 当电源打开时, 电源可能已受限流。不增加当前限制.
</li>
	<li>记录电源显示的电压和电流读数。</li>
	<li>将电压设置为0伏, 并断开电源。</li>
	<li>将当前限制调整为 4, 然后将电源输出连接到次侧绕组 (OUT1 和 OUT2)。保持主侧绕组 (IN1 和 IN2) 打开。</li>
	<li>打开电源, 并稍微增加电压, 直到达到当前限制。请注意, 当电源打开时, 电源可能已受限流。不增加当前限制.
</li>
	<li>记录电源显示的电压和电流读数。对于这个变压器, 输入电压是 3.5 V, 电流是 0.8 A。</li>
	<li>将电压设置回0伏, 关闭电源, 然后断开。</li>
	<li>用多米测量主绕组的电阻。</li>
	<li>通过多米测量二次绕组的电阻。</li>
	<li>这是常见的, 有较高的电压侧电阻高于较低的电压侧阻力, 因为事实是, 双方的权力是理想的平等, 更高的电压意味着较低的电流, 从而降低阻力。在多台仪表上的直流测试和测量电阻应紧密匹配。</li>
</ol>2. 开路试验
<ol><li>确保三相源已关闭。</li>
	<li>连接电路的开路测试 (图 1)。使用数字电能表。</li>
	<li>确保调压器在0%</li>
	<li>双击图1所示的电路连接, 然后打开三相位源。</li>
	<li>慢慢调整调压器旋钮直到数字功率计上的电压读数达到 24 v</li>
	<li>记录电能表的电压、电流、实际功率和功率因数。</li>
	<li>将调压器设置回 0%, 关闭三相位源, 并断开调压器输出。</li>
	<li>在开路或空载试验中, 磁化电抗 (Xm) 和核心损耗电阻 (RC) 从当前 (Ioc)、电压 (Voc) 和电源 (P oc) 中找到。) 度量如下: RC= Voc2/Poc (1) 和Xm= Voc2/Qoc (2) 其中Qoc2=(VocIoc)2 Poc2 (3)</li>
</ol><img alt="Figure 1" src="/files/ftp_upload/10151/10151fig1.jpg"> 图 1: DC 测试示意图<a href="//cloudflare.jove.com/files/ftp_upload/10150/10151fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
3. 短路试验
<ol><li>确保三相源已关闭。</li>
	<li>连接电路的短路测试 (图 2)。确保 IN1 和 IN2 连接到调压器输出。</li>
	<li>确保调压器在0%</li>
	<li>计算变压器的额定输入电流。这是通过将 VA 额定值除以输入端的额定电压来发现的。例如, 如果输入为 115 V, va 额定值为 100 va, 则输入电流额定值为 100/115 = 0.87 A。</li>
	<li>检查电路, 然后打开三相位源。</li>
	<li>慢慢地, 仔细地调整调压器旋钮直到数字功率计上的电流读数达到额定输入电流。</li>
	<li>在电能表上记录电压、电流、实际功率和功率因数。</li>
	<li>将调压器设置回 0%, 关闭断开连接开关, 并断开调压器输出。保持调压器三相电缆连接。</li>
	<li>卸下在变压器次级的短路位置。</li>
	<li>在短路试验中, 漏电抗 (X1+x2= Xeq) 和电阻线 (R从当前 (I SC) 中找到两个绕组的 1 +R2"= req )、电压 (Vsc) 和电源 (Psc) 的测量结果如下: Req=PscIsc2 (4) 和Xeq= QscIsc2 (5) 其中Qsc2=(Vsc Isc)2 Psc2 (6)</li>
	<li>
X1 被假定为等于X2, 而r1 和r2可以从 DC 测试中使用 (或至少其中一个)。如果未执行 DC 测试, 则通常假定R1 和r2是相等的。</li>
</ol><img alt="Figure 2" src="/files/ftp_upload/10151/10151fig2.jpg"> 图 2: 短路测试示意图<a href="//cloudflare.jove.com/files/ftp_upload/10151/10151fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
4. 负载测试
负载测试显示电流和电压值是如何在理想状态下的变压器的输入和输出端之间相互关联的. v1/v2 = I2/我1 = N1/N2 = aN是轮数, 下标1和2分别用于主和次边, 而a是轮流比率。第二侧反射到主侧的阻抗为R "=a2r或X"=a2十 x
<ol><li>确保三相源已关闭。</li>
	<li>连接负载测试的电路 (图 3)。确保 IN1 和 IN2 连接到调压器输出。</li>
	<li>确保调压器在0%</li>
	<li>使用1/200 设置将示波器的差分电压探头连接到主电源。使用适当的比例因子调整 0 V 偏移量的探针测量。</li>
	<li>连接示波器电流探头以测量负载电流。调整探头测量的 0 mv 抵消与1X 缩放因子为 100 mv/一个设置。</li>
	<li>检查电路, 然后打开三相断开开关。</li>
	<li>慢慢调整调压器旋钮直到VP 读取 115 v</li>
	<li>记录两个数字功率计的电压、电流、实际功率和功率因数。</li>
	<li>捕获示波器屏幕, 至少显示三周期。</li>
	<li>关闭三相位源并将调压器设置为0%。</li>
	<li>以并联的三100ω电阻器取代100ω电阻。</li>
	<li>打开三相位源并慢慢调整调压器旋钮, 直到VP读取115五v
</li>
	<li>仅记录两个数字电能表读数 (无示波器屏幕截图)。</li>
	<li>将调压器设置回 0%, 关闭断开连接开关, 然后断开安装。</li>
</ol><img alt="Figure 3" src="/files/ftp_upload/10151/10151fig3.jpg"> 图 3: 负载测试示意图<a href="//cloudflare.jove.com/files/ftp_upload/10151/10151fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

所描述的测试是评价变压器阻抗和确定其等效电路参数的关键。由于变压器的应用不同, 从简单的充电器到大功率的交流输电, 适当的特点不同的变压器, 为各种应用是必不可少的。变压器阻抗用于电力系统, 以确定变压器两侧可能的故障阻抗, 近似变压器的效率, 计算其线路和负载调节, 并模拟变压器的一部分, 较大的电气系统.

单相变压器

资料来源: Bazzi, 康涅狄格州大学电气工程系, 斯托斯, CT。
变压器是一种固定的电动机器, 它能加速或降低交流电压。它们通常是由初级和次级线圈或线圈组成的, 其中主电压在次级或相反方向上向上或向下加强。当电压被应用于绕组中的一个绕组和电流流时, 磁通在磁芯中感应, 耦合两个绕组。在交流电流的作用下, 交流磁通被诱导, 其变化率在二次绕组上产生电压 (法拉第定律)。两绕组之间的磁链连接取决于每个绕组的匝数;因此, 如果主绕组比二次绕组有更多的转弯, 则在主线圈上的电压会比次级线圈高, 反之亦然。
本实验通过寻找其等效电路参数来表征单相变压器。三进行了测试: 开路试验、短路试验和直流试验。

通过执行直流、开路、短路和负载试验, 确定了变压器的等效电路参数;因此, 模拟、操作和分析现实的变压器行为成为可能。
短路测试通常是通过在高压侧施加一个增加的电压来实现的, 因为只有在这一侧的小电压可能导致额定电流在短路的低压侧流动。这是很有用的操作变压器在额定电流, 因此, 测试目前的运载能力。
本测试的短路电压为11.9 伏, 短路电流为 0.865, 短路功率为 7.11 W。然后用短路测量法计算漏电抗, 在这种情况下是9.94Ω的。所产生的主侧和反射侧电抗是每个4.97Ω。总导线电阻计算为9.502Ω。减去主绕组的电阻 (4.375Ω) 给出5.127
对于开路试验, 在运行额定电压时, 确保变压器电压绝缘性能的满足是非常有用的。其他的测试, 如绝缘材料击穿, 机械振动试验等的高罐绝缘试验, 也执行, 但更先进的应用。
对于该变压器, 开路电压为23.8 伏, 开路电流为335.5 毫安, 开路功率为 2.4...

Source: Ali Bazzi, Department of Electrical Engineering, University of Connecticut, Storrs, CT.
Transformers are stationary electric machines that step up ...

单相变压器用于电源和其他设备中，用于将交流电压和电流从一个值转换为另一个值。变压器对于提供电气隔离至关重要，这对于许多实验室仪器和医疗设备的安全运行是必不可少的。如果输入和输出不共享公共端子，则变压器可以在完全物理隔离的情况下传输电力。这可以防止系统危险高压侧的电力到达电路和安全低压侧的人员。了解变压器内的组件对于变压器分析和设计非常重要。本视频将演示如何通过执行各种测试来测量变压器元件的电气参数。变压器有一对连接到初级绕组或线圈的输入端子和一对连接到次级绕组的输出端子。由钢、铁氧体甚至简单的空气组成的磁芯将两个绕组磁耦合。一个绕组上的电压会导致电流流过它，从而产生磁场。磁通量，即通过一个区域的磁场量，然后通过磁芯耦合到次级绕组，在那里感应出电压。这个原则称为互归。法拉第定律指出，磁通量的变化率乘以绕组数等于感应电压。也称为电动势或 EMF。初级绕组两端的直流电压是恒定的，因此产生的磁通量也是恒定的，变化率为零。然而，交流电压会产生变化率不为零的磁通量，从而感应出电压。换句话说，变压器需要交流电压才能运行。变压器匝数比是初级绕组上的导线匝数除以次级绕组上的匝数。初级两端的电压与次级两端的电压之比等于匝数比。根据匝数比，变压器可以提高电压、降低电压或保持相同。通过初级的电流与通过次级的电流之比等于匝数比的倒数。例如，如果初级线圈有 3 匝，次级线圈有 30 匝，则匝数比为 0.1。因此，该变压器初级上的 120 伏特变为次级上的 1200 伏特。通过初级的 10 安培通过次级变为 1 安培通过次级。最后，如果次级线圈的负载为 Z2 阻抗，则初级线圈具有视在或反射负载 Z2 素数。该反射负载的值是次级侧的阻抗乘以匝数比的平方。变压器可以看作是一对耦合电感器，理想情况下，它可以无损耗地将能量从一个线圈传输到另一个线圈。然而，真正的变压器漏磁通量或漏感，这无助于绕组之间的能量转移。此外，真正的变压器会受到绕组电阻的功率耗散和发热。由于磁芯损耗电阻，磁芯中感应的磁通量是额外的热源。为避免损坏，使用指定的最大功率输入，称为 VA 额定值或输入电压与电流的乘积，即功率。现在已经介绍了变压器的基础知识，让我们来看看如何测量变压器的电气参数。本实验中使用的变压器的额定电压为初级绕组最大 115 伏，次级绕组最大可承受 24 伏。此外，该变压器的额定功率为 100VA，这意味着它最多可以接受 100 瓦的功率。该直流测试测量每个绕组的电阻，用于变压器的等效电路模型。首先将低压直流电源电压输出设置为 0 伏，电流限制设置为 0.8 安培。然后关闭电源。将电源输出连接到初级绕组上。请勿将任何东西连接到次级绕组。打开直流电源并逐渐增加电压，直到达到电流限制。记录电源显示屏上的电压和电流读数。通过将电压除以电流来计算初级绕组的电阻。将电源电压设置回零伏特并将其关闭。将电源跨过次级绕组，在初级绕组上留下开路。将电源的电流限制设置为 4 安培。然后逐渐增加电压，直到达到电流限制。记录电源显示屏上的电压和电流读数。计算次级绕组的电阻。将电源电压设置回零伏，将其关闭并断开与变压器的连接。最后，使用万用表确认计算出的初级和次级绕组电阻。开路测试测量相互反应物或对磁芯损耗电阻电流变化的反对。磁芯损耗电阻是功率耗散的等效电路参数，近似于变压器磁芯中的功率损耗。在三相电源关闭且 Variac 设置为零的情况下，如图所示组装电路。然后使用数字功率计测量初级侧的开路电流和电压。打开三相电源，慢慢调整 Variac 的控制旋钮以增加电压，直到数字功率计读数为 24 伏。记录开路电压、开路电流、开路有功功率和功率因数。使用这些值可以计算变压器的等效电路参数。磁芯损耗电阻 RC 由开路电压和开路功率计算得出。互抗 XM 使用开路电压、功率和电流类似地计算。短路测试测量泄漏反应物，还可以确定两个绕组的导线电阻。首先，通过将 VA 额定值除以输入侧的额定电压来计算变压器的额定输入电流。在电源关闭的情况下，Variac 以 0% 输出组装电路，如图所示。这一次使用数字功率计测量短路电流和电压。打开三相电源，慢慢调整 Variac 以增加电压，直到数字功率计上的电流读数达到额定输入电流。记录短路电压和电流以及短路有功功率和功率因数。泄漏反应物是假设相等的初级副反应物和反射的次级副反应物的总和。使用短路测试的测量值计算泄漏反应物。最后，将两个绕组的总导线电阻计算为初级绕组的电阻和次级侧绕组的反射电阻之和。变压器是非常有用的电气设备，可用于电源转换和安全电气隔离领域。负载测试测量初级两端的电压与次级两端的电压之比，以及通过初级的电流与通过次级的电流的比值。该电路由连接到次级侧的 100 欧姆电阻器组装而成，并在两侧测量电流和电压。初级侧为 115 伏，测量两侧的电压、电流、有功功率和功率因数。理想情况下，初级电压与次级电压的比值应等于匝数比。一项对小鼠嗅觉感觉神经元的研究使用来自氙气闪光灯管的紫外线来解离某些化合物。驱动闪光管的电路需要由升压变压器产生高电压。与所有高压设备一样，安全设计使用变压器进行电气隔离，以防止具有危险电压的组件与电路中的其他电子设备之间发生意外短路。您刚刚观看了 Jove 对单相变压器的介绍。您现在应该了解变压器的工作原理以及如何测量其等效电路参数。感谢观看！

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single phase transformer testing

Single-phase transformers step up or step down AC voltage in electric power systems. They are stationary electric machines with primary and secondary coils, also called windings. The primary winding receives the applied voltage, and the secondary winding delivers the changed voltage.

Inside the transformer, current in one winding creates magnetic flux in the core. This flux links the two windings and transfers energy between them. With AC current, the changing flux induces voltage in the secondary winding by Faraday's law. The voltage change depends on the number of turns in each winding. If the primary has more turns than the secondary, the primary voltage is higher. If the secondary has more turns, the secondary voltage is higher.

This experiment characterizes a single-phase transformer by finding its equivalent circuit parameters. It uses three tests: the open-circuit test, the short-circuit test, and the DC test. These measurements help describe how the transformer behaves under different conditions.

Single Phase Transformer Testing

electrical safety precautions and basic equipment

electrical-safety-precautions-and-basic-equipment

Safe Handling of High-Voltage Lab Power

Safe handling of high-voltage lab power is essential in electric machine and power electronics experiments. These labs involve electrical currents, voltages, power, and energy that require extreme care. The systems used in this work can include three-phase AC voltage at 208 V, 230 V, or 480 V. They may also use up to 250 V DC and currents that can reach 10 A. These levels can be dangerous if handled without proper attention. Electrocution can happen when electricity passes through the body.

characterization of magnetic components

B-H Curves and Inductor Core Limits

Magnetic components such as inductors and transformers depend on the core material around their windings. In this experiment, students get hands-on experience with these parts from both a design view and a material view. The work focuses on B-H curves, which show the magnetic behavior of a material. A B-H curve describes the magnetic flux density the core can support as current flows through the windings. It also helps show the limit before magnetic saturation occurs. Magnetic saturation...

introduction to the power pole board

Power Pole Board for DC/DC Converter Labs

The HiRel Power Pole Board is a flexible tool for studying DC/DC converters. A DC/DC converter changes direct-current voltage and current from one level to another. In many cases, voltage conversion is the main goal. This board supports several converter types on one platform. It can be used to examine boost converters, which step voltage up, and buck converters, which step voltage down. It also helps students study buck-boost converters, which can step voltage up or down. The board is also...

dc/dc boost converter

Stepping Up DC Voltage with Boost Converters

DC voltage can be increased with a boost converter. This step-up circuit is useful in many applications where a DC source must be raised without first converting it to AC, using a transformer, and then rectifying the transformer output. A boost converter uses an inductor as an energy storage device. The inductor supports the output with extra energy in addition to the DC input source. That added energy raises the output voltage. This experiment studies several characteristics of a boost...

dc/dc buck converter

Buck Converter Step-Down DC Voltage

A DC/DC buck converter steps down DC voltage in an efficient, regulated way. Unlike transformers, which easily raise or lower AC voltage and current, DC systems need switching power converters to change voltage levels. The buck converter works by chopping the input DC voltage with a series input switch. An L-C low-pass filter then smooths the chopped signal and extracts the average output voltage. A diode gives the inductor current a path when the switch is off during part of the switching...

flyback converter

Flyback Converter Voltage Step-Up and Step-Down

A flyback converter is a buck-boost converter that can both step voltage up and step it down. It also provides electrical isolation between the input and the output by using a coupled inductor, or flyback transformer. The coupled inductor acts like a transformer with a turns ratio, but it also stores energy through the air gap. This setup gives the converter both voltage step-up and step-down capability. In the experiment, the converter is studied in open-loop operation with a manually set...

single phase transformers

Single-phase transformers step up or step down AC voltage in electric power systems. They are stationary electric machines with primary and secondary coils, also called windings. The primary winding receives the applied voltage, and the secondary winding delivers the changed voltage. Inside the transformer, current in one winding creates magnetic flux in the core. This flux links the two windings and transfers energy between them. With AC current, the changing flux induces voltage in the...

single phase rectifiers

AC to DC Conversion with Rectifiers

Rectifiers convert AC power into DC power for electronic circuits. A DC power supply provides unidirectional voltage and current. Batteries can do this, but they are limited by lifetime and cost. Using a rectifier is another way to turn AC line power into DC power. A rectifier is a device that lets current pass in one direction and blocks it in the other. It works after a forward voltage threshold is reached. Rectifiers may use a diode, a silicon controlled rectifier, or other silicon P-N...

thyristor rectifier

Controlling SCR Half-Wave Rectification

Thyristors, also called silicon controlled rectifiers (SCRs), are used to control current in a rectifier circuit. Like diodes, they let current pass from the anode to the cathode and block current in the opposite direction. Unlike a diode, a thyristor can be turned on with a gate terminal that receives a small current pulse. A thyristor is a four-layer device with alternating n-type and p-type layers. These layers form a PNPN structure with three junctions. The device has three terminals. The...

single phase inverter

DC to AC Conversion with Half-Bridge Inverters

DC to AC conversion is the main idea behind a power inverter. DC power flows in one direction, while AC current changes direction at about 50-60 Hz. Many electronic devices are designed to run on AC power, so a DC source must be inverted before it can be used with them. An inverter makes this change through switching action. The switches repeatedly flip the polarity of the input DC source at the output, or load side, for part of a switching period. A typical power inverter needs a stable DC...

dc motors

DC Motors and Generator Action

DC machines use direct current and direct voltage to create motion or generate electricity. They were the first machines of this kind to be invented. A DC machine works with two magnetic fields that are controlled by DC currents, and the same machine can be set up as either a motor or a generator when the right field excitation is available. In a DC machine, the field is usually on the stator side and the armature is on the rotor side. That arrangement is the reverse of what is found in many...

ac induction motor characterization

Three-Phase Motor Equivalent Circuit Tests

Three-phase induction motor testing can be used to find equivalent circuit parameters. The experiment uses the per-phase equivalent circuit to model the motor. This model keeps the important behavior of the original system and makes calculations easier. The procedure uses tests similar to those used in transformer characterization. These measurements help estimate the motor's circuit values from its electrical response. The experiment also aims to operate the motor in the linear torque-speed...

vfd-fed ac induction machine

Variable Frequency Drive Speed Control

Variable frequency drives, or VFDs, control the speed of AC induction motors. They are a type of adjustable speed drive and are becoming standard equipment for powering most AC induction motors. In industrial and automation settings, VFDs can provide strong control of motor speed, torque, or position. This experiment focuses on speed control with open-loop operation. It uses constant voltage-to-frequency ratio control, also called V/f control. The motor usually operates at a rated stator flux,...

ac synchronous machine synchronization

Grid Connection of AC Synchronous Generators

AC synchronous generators are a major source of electrical power worldwide. They are three-phase, wound-rotor machines that are used in many power plants. These generators need a prime mover and an exciter to produce power. A prime mover is the device that spins the generator, often a turbine driven by fluid. That fluid can come from water flowing from a dam through a long nozzle or from steam made by burning coal. Most power plants use synchronous generators, including coal, nuclear, natural...

ac synchronous machine characterization

Three-Phase Synchronous Motor Starting and V-Curves

Three-phase synchronous motors and generators are important AC machines. Wound-rotor synchronous motors are less common than permanent magnet rotor synchronous motors because the rotor field uses brushes. Synchronous generators are much more common. They are used in most existing power plants because they provide excellent frequency and voltage regulation. A synchronous motor runs at the same speed as the stator magnetic field. This gives it almost 0% speed regulation, so the rotor speed stays...

electrical engineering

本系列从电气安全视频开始, 介绍了电气实验室中常用设备的最佳实践。随后的视频介绍了电感器、变压器、变流器、整流器和逆变器等元素。

Learn how a single-phase transformer works and how open-circuit, short-circuit, and DC tests are used to find its equivalent circuit parameters.

Single Phase Transformer Testing | JoVE K12

Ali Bazzi

Overview

Principles of Single-phase Transformers

DC Test for Winding Resistance

Open Circuit Test

Short Circuit Test

Applications

Summary

Newton's Second Law

Newton&#39;s second law is closely related to his first law of motion. It mathematically gives the cause-and-effect relationship between force and changes ...

Second Law: Motion under Same Force

Newton&#39;s laws can be applied to bodies at rest and bodies in motion. Newton&#39;s first law is applied to bodies in equilibrium, whereas the second ...

Force and Acceleration

Source: Nicholas Timmons,&#160;Asantha Cooray, PhD, Department of Physics &#38; Astronomy, School of Physical Sciences, University of California, Irvine, ...

second-law-motion-under-same-acceleration

Second Law: Motion under Same Acceleration

Newton&#39;s second law of motion applies to bodies moving under the same acceleration. For example, when a baggage tractor pulls luggage carts, each cart ...

Newton's Laws of Motion

Source: Andrew Duffy, PhD, Department of Physics, Boston University, Boston, MA
This experiment examines at various situations involving two interacting ...

Newton's Law of Motion

When we observe objects around us, one question that comes to mind is why they move or stay still. The answer to this question can be explained using ...

Analyze data to support the claim that Newton's second law of motion describes the mathematical relationship among the net force on a macroscopic object, its mass, and its acceleration.

P-PS2-1

Force and Momentum

Force and momentum are intimately related. Force acting over time can change momentum, and Newton&#39;s second law of motion can be stated in its most ...

Internal and External Forces

Newton&#39;s first law states that a net external force causes a change in motion. External forces act on an object or system, originating outside of the ...

Conservation of Momentum: Introduction

The total momentum of a system consisting of N interacting objects is constant in time or is conserved. A system must meet two requirements for its ...

Force

Forces affect every moment of our life. Our bodies are held to the Earth by force, and they are held together by the forces of charged particles. When we ...

Conservation of Momentum

Conservation of Momentum: Problem Solving

Solving problems using the conservation of momentum requires four basic steps:

	Identify a closed system, where the total mass is constant, and no net ...

conservation-of-linear-momentum-for-a-system-of-particles

Conservation of Linear Momentum for a System of Particles

In a game of billiards, when the cue ball strikes a stationary ball, it transfers some of its momentum to the stationary ball. The cue ball slows down, ...

principle-of-linear-impulse-and-momentum-for-a-system-of-particles

Principle of Linear Impulse and Momentum for a System of Particles

Consider a system of particles moving relative to an inertial frame of reference.
The equation of motion for such a system can be written as the sum of ...

Use mathematical representations to support the claim that the total momentum of a system of objects is conserved when there is no net force on the system.

P-PS2-2

principle-of-linear-impulse-and-momentum-for-a-single-particle

Principle of Linear Impulse and Momentum for a Single Particle

Linear momentum is a fundamental concept in physics that describes the motion of an object. It is a vector quantity, having a magnitude equal to the ...

principle-of-angular-impulse-and-momentum-problem-solving

Principle of Angular Impulse and Momentum: Problem Solving

Consider a ball of mass m, attached to a massless rod of known length, subjected to a time-dependent torque. If the initial velocity of the mass is known, ...

Linear Momentum

The term momentum is used in various ways in everyday language, most of which are consistent with the precise scientific definition. Generally, momentum ...

principle-of-angular-impulse-and-momentum

Principle of Angular Impulse and Momentum

The angular impulse and momentum principle provides insights into how forces applied at a distance from an object&#39;s rotational axis influence its ...

principle-linear-impulse-momentum-for-single-particle-problem

Principle of Linear Impulse and Momentum for a Single Particle: Problem Solving

Consider a massless pulley system consisting of a wooden box and a cylinder of known masses. Determine the speed of the attached objects at a specific ...

Angular Momentum

Angular momentum describes the rotational motion of an object.
It is defined as the moment of the object&#39;s linear momentum about a specific point O.
...

relation-between-moment-of-a-force-and-angular-momentum

Relation Between Moment of a Force and Angular Momentum

In a spinning top, applying a force at a distance from the center creates torque, which changes the angular momentum of the top, causing it to spin.
The ...

Apply scientific and engineering ideas to design, evaluate, and refine a device that minimizes the effect of a force on a macroscopic object during a collision.

P-PS2-3

Gravitation

In the years before Newton, a general belief prevailed that different laws governed objects in the sky than objects on Earth. When Kepler wrote down the ...

/files/media/science-education/science-education-thumbs/14716.jpg

Newton's Law of Gravitation

Our everyday observation tells us that all objects close to the Earth naturally tend to fall to the ground. Early philosophers assumed that this downward ...

gravitation-between-spherically-symmetric-masses

Gravitation Between Spherically Symmetric Masses

The gravitational potential energy between two spherically symmetric bodies can be calculated from the masses and the distance between the bodies, ...

/files/media/science-education/science-education-thumbs/14717.jpg

Gravity between Spherical Bodies

Newton&#39;s law of gravitation describes the gravitational force between any two point masses. However, for extended spherical objects like the Earth, ...

Coulomb's Law

Experiments with electric charges have shown that if two objects each have an electric charge, they exert an electric force on each other. The magnitude ...

comparison-between-electrical-and-gravitational-forces

Comparison Between Electrical And Gravitational Forces

There are four fundamental forces in nature: the gravitational force, the electromagnetic force, the strong nuclear force, and the weak nuclear force. To ...

Newton's Law of Gravitational Attraction

Sir Isaac Newton established the universality of the law of gravitational attraction based on empirical evidence and inductive reasoning. He published his ...

Newton's Law of Universal Gravitation

Source: Ketron Mitchell-Wynne, PhD,&#160;Asantha Cooray, PhD, Department of Physics &#38; Astronomy, School of Physical Sciences, University of ...

Use mathematical representations of Newton's law of gravitation and Coulomb's law to describe and predict the gravitational and electrostatic forces between objects.

P-PS2-4

Types of Forces

In most situations, forces can be grouped into two categories: contact forces and field forces.&#160; Contact forces occur as a result of direct physical ...

Magnetic Fields

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
Magnetic fields can be ...

Electric Charge in a Magnetic Field

Source: Andrew Duffy, PhD, Department of Physics, Boston University, Boston, MA
This experiment duplicates J.J. Thomson's famous experiment at the end of ...

Electric Fields

Source: Yong P. Chen, PhD, Department of Physics &#38; Astronomy, College of Science, Purdue University, West Lafayette, IN
An electric field is generated ...

Electromagnetic Fields

Electric fields generated by static charges, often referred to as electrostatic fields, are characteristically different from electric fields created by ...

Magnetic Field Due to Two Straight Wires

Consider two parallel straight wires carrying a current of 10 A and 20 A in the same direction and separated by a distance of 20 cm. Calculate the ...

Energy Carried By Electromagnetic Waves

Anyone who has used a microwave oven knows there is energy in electromagnetic waves. Sometimes, this energy is obvious, such as in the summer sun&#39;s ...

Energy Stored in Capacitors

A parallel plate capacitor connected to a battery develops a potential difference across its plates.
By integrating the equation relating voltage and ...

Power and Energy

Energy is the total work required to drive the current through the circuit.
A rise in voltage results in more work done, passing more current, resulting ...

Voltage

The movement of electrons in a conductor requires some form of energy or work, usually provided by an external force, like a battery. This force is called ...

Electromotive Force

Electromotive force (emf) is the force that causes current to flow from a higher to a lower&#160; potential. The term &#34;electromotive ...

Electrical Energy

Using electric appliances for a longer period of time consumes more electrical energy and results in a higher electric bill. The energy produced by the ...

Electrical Current

Electrical current is defined as the rate at which charge flows. When there is a large current present, such as that used to run a refrigerator, a large ...

Electric Potential Energy

When an electric field accelerates a free positive charge q, it is given kinetic energy. The process is analogous to an object accelerated by a ...

Electrical Power

Electric power is the product of current and voltage, represented in units of joules per second, or watts. For example, cars often have one or more ...

Plan and conduct an investigation to provide evidence that an electric current can produce a magnetic field and that a changing magnetic field can produce an electric current.

P-PS2-5

sources-and-properties-of-electric-charge

Sources and Properties of Electric Charge

All objects we see around us consist of atoms, which combine to form molecules. The lightest element in the universe is hydrogen, and a hydrogen atom ...

Electric Charges

From lightning during thunderstorms to electronic devices, the phenomenon of electromagnetism is all around us. The electromagnetic force is one of the ...

Electron Behavior

Electrons are negatively charged subatomic particles attracted to and orbit around the positively-charged nucleus of an atom. They reside in spaces ...

Electronic Structure of Atoms


An atom comprises protons and neutrons, which are contained inside the dense, central&#160;core called the nucleus, with electrons present around the ...

Communicate scientific and technical information about why the molecular-level structure is important in the functioning of designed materials.

Single Phase Transformer Testing

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