Question
What is a transformer? Write down its working principle and construction.

Answer

The device using which alternating voltage can be changed from one to another of greater or smaller value, is called a transformer.
• Principle :
Electro magnetic induction (Mutual induction)
• Construction :
A transformer consists of two sets of coils, insulated from each other. They are wound on a soft iron core, either on top of the other as in fig. (a) or on separate limbs of the core as shown in (b).
Image
One of the coils is called the primary coil and the other is called the secondary coil.
Number of turns in the coils are $N _{ P }$ and $N _{ S }$ respectively.
Often, the primary coil is the input coil and the secondary coil is the output coil of the transformer.
When an alternating voltage is increased using a transformer, it is called step up transformer, and if the voltage is decreased, the transformer is known as step down transformer.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

By what fraction does the mass of a spring change when it is compressed by 1cm? The mass of the spring is 200g at its natural length and the spring constant is 500N/m.
A ball of superconducting material is dipped in liquid nitrogen and placed near a bar magnet.
i. In which direction will it move?
ii. What will be the direction of its magnetic moment?
The force on a north pole,$\overrightarrow{\text{F}}=\text{m}\overrightarrow{\text{B}},$ is parallel to the field $\overrightarrow{\text{B}}.$ Does it contradict our earlier knowledge that a magnetic field can exert forces only perpendicular to itself?
An alpha particle is projected vertically upward with a speed of $3.0 \times 10^4\ km s^{-1}$ in a region where a magnetic field of magnitude $1.0T$ exists in the direction south to north. Find the magnetic force that acts on the $\alpha -$particle.
Show that the electrostatic potential is constant throughout the volume of the conductor and has the same value (as inside) on its surface.
If an object far away from a convex mirror moves towards the mirror, the image also moves. Does it move faster, slower or at the same speed as compared to the object?
The distance between the cathode (filament) and the target in an X-ray tube is 1.5m. If the cutoff wavelength is 30pm, find the electric field between the cathode and the target.
Is there any lower limit to the electric force between two particles placed at a separation of 1cm ?
A nearsighted person cannot clearly see beyond 200cm. Find the power of the lens needed to see objects at large distances.
Let $\vec{\text{A}}=3\vec{\text{i}}+4\vec{\text{j}}.$ Write four vector $\overrightarrow{\text{B}}$ such that $\overrightarrow{\text{A}}\neq\overrightarrow{\text{B}}$ but A = B.