Electromagnetism

Question 1:A step-down transformer is connected to an alternating current power supply. Explain the working principle of the transformer. Answer:The alternating voltage produces an alternating current in the primary coil.The alternating current produces a changing magnetic field.The magnetic field is linked to the secondary coil through the soft iron core.The changing magnetic field induces an … Read more

Question 1:What is the meaning of electromagnetic induction? Answer:Electromagnetic induction is the production of an induced e.m.f. in a conductor when there is relative motion between the conductor and a magnetic field or when the conductor is in a changing magnetic field. Question 2:(a) State Faraday’s law.(b) Use Faraday’s law to explain the effect of … Read more

Question 1:With the aid of a labelled diagram, explain the meaning of catapult field. Answer:A catapult field is a resultant magnetic field produced by the interaction between the magnetic field from a current-carrying conductor with the magnetic field from a permanent magnet. Question 2:Figure 4.15 shows the arrangement of apparatus to study the effect of … Read more

Question 6:Figure 5 shows a wooden block with a bar magnet tied to it sliding with an acceleration down a smooth track.When the block arrives at mark X on the track, the switch is turned on.(a) What is produced in the solenoid? Explain your answer.(b) Explain the motion of the block after the switch is … Read more

Question 3:Figures 2 and 3 show the induced currents produced when there is relative motion between a bar magnet and a solenoid.(a) What is the meaning of induced current?(b) Based on the direction of the current given in Figures 2 and 3, state the magnetic polarities at ends X and Y of the solenoid.(c) State … Read more

Question 1:Figure 1 shows a conductor hanging from a sensitive spring balance in between a pair of Magnadur magnets.(a) Suggest the polarity of dry cell X, Y and the polarity of magnets P, Q such that the reading of the spring balance increases when switch S is turned on.(b) Explain why the reading of the … Read more

Q: Why the voltage is stepped up before transmitting electricity over a long distance? A: Stepping up the voltage can reduce the current in the cable. This reduces the power loss in the cable during transmission. [This image is shared by its author Aatu Liimatta in Wikipedia Image. This file is licensed under the Creative … Read more

Wind Power[This image is shared by Wagner Christian. This file is licensed under the Creative Commons Attribution ShareAlike 2.5 License. ] Advantages The advantages of using wind as a source of energy to generate electricity are. It is renewable energy. It does not pollute the environment. It is suitable for the mountain area because the wind speed in the mountain … Read more

Biomass is biological material derived from living organisms such as wood and animal waste. As a renewable energy source, biomass can either be used directly via combustion to produce heat or indirectly after converting it to various forms of biofuel. Heat energy produced from the burning of biomass can be used to generate electricity. Advantages … Read more