Advertisements
Advertisements
प्रश्न
Explain the significance of Lenz’s law to show the conservation of energy in electromagnetic induction.
Advertisements
उत्तर
Lenz's law implies the law of conservation of energy. It shows that the mechanical energy spent in doing work, against the opposing force experienced by the moving magnet, is transformed into the electrical energy due to which current flows in the solenoid.
संबंधित प्रश्न
Which coil of a step up transformer is made thicker and why?
Why is the iron core of a transformer made laminated (thin sheets) instead of being in one solid piece?
What is the ideal transformer?
What is the function of a step-up transformer?
State the mathematical relation between a number of turns in the primary coil to a secondary coil in the step-up transformer.
Read the following paragraph and answer the question:
Long distance power transmissions
The large-scale transmission and distribution of electrical energy over long distances is done with the use of transformers. The voltage output of the generator is stepped up. It is then transmitted over long distances to an area sub-station near the consumers. There the voltage is stepped down. It is further stepped down at distributing sub-stations and utility poles before a power supply of 240 V reaches our homes.
Which of the following statement is true?
A transformer is essentially an a.c. device. It cannot work on d.c. It changes alternating voltages or currents. It does not affect the frequency of a.c. It is based on the phenomenon of mutual induction. A transformer essentially consists of two coils of insulated copper wire having different numbers of turns and wound on the same soft iron core.
The number of turns in the primary and secondary coils of an ideal transformer is 2000 and 50 respectively. The primary coil is connected to a main supply of 120 V and secondary coil is connected to a bulb of resistance 0.6 Ω.
The value of voltage across the secondary coil is ______.
A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10 A, then the input voltage and current in the primary coil are ______.
How is the laminated soft iron core made?
Assuming no flux leakage, which coils does the changing flux thread through?
