Electromagnetism
Muhtasari
Every electric motor, every loudspeaker and every MRI scanner relies on the same principle: a current flowing through a magnetic field experiences a force. Electromagnetism connects electricity to magnetism and puts that connection to work in devices you use every day.
In this lesson you will trace the magnetic field around a current-carrying wire, build it into a solenoid, strengthen it into an electromagnet, and then apply Fleming's left-hand rule to predict forces. You will see how those forces drive a d.c. motor and make a loudspeaker cone vibrate to produce sound.
Malengo
- Know that an electric current in a conductor produces a magnetic field around it
- Describe the construction of electromagnets
- Draw magnetic field patterns for a straight wire, a flat circular coil and a solenoid when each is carrying a current
- Know that there is a force on a charged particle when it moves in a magnetic field as long as its motion is not parallel to the field
- Understand why a force is exerted on a current-carrying wire in a magnetic field and how this effect is applied in simple d.c. electric motors and loudspeakers
- Use the left-hand rule to predict the direction of the resulting force when a wire carries a current perpendicular to a magnetic field
- Describe how the force on a current-carrying conductor in a magnetic field changes with the magnitude and direction of the field and current
Ramani ya mawazo
Mada hii imechorwa ili uone jinsi mawazo yanavyounganika.
Fungua ramani ya mawazo kwenye programu
Kadi za kumbukumbu
Mazoezi ya haraka ya kumbukumbu kuhusu kinachopimwa katika mada hii.
Fanya mazoezi ya kadi hizi kwenye programu
Maelezo ya Somo
Dokezo Kamili la Somo Linapatikana kwenye Programu ya Green Bridge
Pata programu ya Green Bridge CBT kwenye simu au kompyuta yako kwa maktaba kamili ya IGCSE: mitihani ya miaka iliyopita, miongozo ya usahihishaji, ramani za mawazo, kadi za marudio na masomo ya sauti.
Tathmini ya Somo
Hongera kwa kukamilisha somo la Electromagnetism. Sasa kwa kuwa umechunguza dhana na mawazo muhimu, ni wakati wa kuweka ujuzi wako kwa mtihani. Sehemu hii inatoa mazoezi mbalimbali maswali yaliyoundwa ili kuimarisha uelewaji wako na kukusaidia kupima ufahamu wako wa nyenzo.
Utakutana na mchanganyiko wa aina mbalimbali za maswali, ikiwemo maswali ya kuchagua jibu sahihi, maswali ya majibu mafupi, na maswali ya insha. Kila swali limebuniwa kwa umakini ili kupima vipengele tofauti vya maarifa yako na ujuzi wa kufikiri kwa makini.
Tumia sehemu hii ya tathmini kama fursa ya kuimarisha uelewa wako wa mada na kubaini maeneo yoyote ambapo unaweza kuhitaji kusoma zaidi. Usikatishwe tamaa na changamoto zozote utakazokutana nazo; badala yake, zitazame kama fursa za kukua na kuboresha.
- What shape is the magnetic field around a straight current-carrying wire? A) Straight parallel lines B) Concentric circles C) Radial lines pointing outward D) A single loop Answer: B
- Which of the following will NOT increase the strength of an electromagnet? A) Increasing the current B) Adding more turns to the coil C) Using a copper core D) Using a soft iron core Answer: C
- In Fleming's left-hand rule, what does the thumb represent? A) Current B) Magnetic field C) Force D) Voltage Answer: C
- A wire carries a current of 6.0 A through a 0.50 T field. The wire is 0.20 m long. What is the force on the wire? A) 0.06 N B) 0.60 N C) 6.0 N D) 60 N Answer: B
- What is the role of the split-ring commutator in a d.c. motor? A) It increases the current B) It reverses the current direction every half-turn C) It strengthens the magnetic field D) It provides the power supply Answer: B
Fanyia kazi maswali haya kwenye programu
Fanyia kazi maswali haya kwenye programu
Vitabu Vinavyopendekezwa
Jifunze zaidi kutoka vyanzo huria
-
Sehemu ya kitabu
Magnetic Fields, Field Lines, and Force
Summarize properties of magnets and describe how some nonmagnetic materials can become magnetized
"Physics: Magnetic Fields, Field Lines, and Force" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/physics/pages/20-1-magnetic-fields-field-lines-and-force. Access for free at https://openstax.org/books/physics/pages/1-introduction
-
Sehemu ya kitabu
Torque on a Current Loop: Motors and Meters
Motors are the most common application of magnetic force on current-carrying wires. Motors have loops of wire in a magnetic field. When current is passed through the loops, the magnetic field exerts torque on the loops, which rotates a shaft. Electrical energy is converted to mechanical work in the
"College Physics: Torque on a Current Loop: Motors and Meters" by OpenStax, OpenStax, Rice University, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Source: https://openstax.org/books/college-physics/pages/22-8-torque-on-a-current-loop-motors-and-meters. Access for free at https://openstax.org/books/college-physics/pages/1-introduction
Vimechapishwa na mashirika mengine chini ya leseni huria na vinatajwa kama wanavyoomba. Viungo hufungua tovuti zao.
Fanya Mazoezi ya Maswali ya Majaribio
Ungependa kufanya mazoezi ya maswali ya majaribio kuhusu Electromagnetism? Pakua programu ya Green Bridge CBT ili kupata maswali ya majaribio na tathmini kamili za mazoezi kuhusu mada hii.
Pakua Programu Kwenye Google Playstore
Kila kitu unachohitaji ili kufaulu katika JAMB, WAEC & NECO.
