Advertisements
Advertisements
प्रश्न
Why is the core of a transformer laminated?
Advertisements
उत्तर
The core of a transformer is laminated to reduce the energy loss due to eddy currents.
APPEARS IN
संबंधित प्रश्न
Write the function of a transformer.
The primary coil of an ideal step-up transformer has 100 turns and the transformation ratio is also 100. The input voltage and power are 220 V and 1100 W, respectively. Calculate the
(a) number of turns in secondary
(b) current in the primary
(c) a voltage across secondary
(d) current in secondary
(e) power in secondary
What type of current is transmitted from the power station?
Explain the significance of Lenz’s law to show the conservation of energy in electromagnetic induction.
The following diagram in Fig.10.42 shows a coil of several turns of copper wire connected to a sensitive centre zero galvanometer G near a magnet NS. The coil is free to move in the direction shown in the diagram.
(i) Describe the observation if the coil is rapidly moved.
(ii) How would the observation be altered if (a) the coil has twice as many turns (b the coil was made to move three times as fast?
In a transformer, the frequency of A.C. voltage ______.
What is the function of a transformer in an a.c. circuit? How do the input and output powers in a transformer compare?
The input and output voltages of a transformer are 220 V and 44V respectively. Find the current in input circuit if the output current is 2 A.
Name three losses of energy in a transformer. How are they minimized?
The primary coil of a transformer has 200 turns while the secondary coil has 1000 turns. What type of transformer is this? if the input voltage is 10V, what will be the output voltage?
The primary of a transformer has 40 turns and works on 100 V and 100 W. Find a number of turns in the secondary to step up the voltage to 400 V. Also calculate the current in the secondary and primary.
Describe the construction and working of a transformer with a neat labelled diagram.
A step-down transformer connected to the main supply of 220 V is used to operate 11V,88W lamp. Calculate
- Voltage transformation ratio and
- Current in the primary
A 100% efficient transformer has 100 turns in the primary and 50 turns in its secondary coil. If the current in the secondary coil is 6 A, then the current in the primary coil is ______.
A 60 W load is connected to the secondary of a transformer whose primary draws line voltage. If a current of 0.54 A flows in the load, what is the current in the primary coil? Comment on the type of transformer being used.
What type of transformer is used in a mobile phone charger?
A 12 V, 60 W lamp is connected to 220 V AC via an ideal transformer. Find the primary current.
In an ideal transformer, the turns ratio is `N_p/N_s = 1/2`. The ratio Vs : Vp is equal to (the symbols carry their usual meaning):
