Electricity and Magnetism - SS1 Physics Past Questions and Answers - page 4
Which principle of electromagnetic induction is primarily used in a transformer?
Faraday's law of electromagnetic induction
Lenz's law
Ampere's law
Ohm's law
In a transformer, if the number of turns in the primary coil is greater than the number of turns in the secondary coil, what will be the effect on the output voltage?
The output voltage will increase
The output voltage will decrease
The output voltage will remain the same
It depends on the power supply
Which of the following materials is commonly used as the core in a transformer?
Copper
Aluminium
Steel
Silver
Transformers are most commonly used in which type of electrical power distribution?
Direct current (DC) distribution
Battery-powered devices
Alternating current (AC) distribution
High-voltage transmission lines
What is the purpose of the iron core in a transformer?
To increase the voltage
To decrease the voltage
To provide a conducting path for current flow
To increase the efficiency
What is the primary reason for using a high-frequency alternating current (AC) in some transformers?
To reduce energy losses
To increase the power output
To improve voltage regulation
To decrease the physical size of the transformer
Which of the following is not a type of transformer?
Step-up transformer
Step-down transformer
Isolation transformer
Capacitor transformer
What is the main advantage of using a transformer in electrical power transmission?
It reduces the transmission losses
It eliminates the need for power plants
It provides backup power during outages
It increases the overall efficiency of the system
Describe the working principle of a transformer. How does it transfer electrical energy from one coil to another? Discuss the role of electromagnetic induction in this process.
A transformer works on the principle of electromagnetic induction. It consists of two coils, the primary coil and the secondary coil, which are wound around a common magnetic core. When an alternating current (AC) is applied to the primary coil, it generates a changing magnetic field. This changing magnetic field induces an alternating voltage in the secondary coil through electromagnetic induction. The voltage induced in the secondary coil is directly proportional to the turn ratio between the two coils. This allows the transformer to step up or step down the voltage based on the ratio of turns in the coils.
Discuss the applications of transformers in various industries and everyday life. Provide examples of how transformers are used to meet different electrical power requirements.
Transformers have numerous applications in various industries and everyday life. Some common examples include:
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Power transmission and distribution: Transformers are used in power grids to step up the voltage for efficient long-distance transmission and step it down for distribution to homes and industries.
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Electrical appliances: Transformers are used in electronic devices such as televisions, computers, and mobile phone chargers to provide the required voltage levels for their operation.
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Industrial applications: Transformers are used in industrial equipment.