A static electrical device has 2000 turns uses 4000 mA from the supply connected to a laptop which has a power of 20 V, 1000 W. How can you find the amount of current used by the laptop? Identify such static electrical device used and evaluate supply voltage taken by it. Which category does it belong based on its ability to change voltage? Practical efficiency of such electrical device is less than 100 %. Justify with reasons. What are possible ways to improve its efficiency?
A static electrical device has 2000 turns uses 4000 mA from the supply connected to a laptop which
has a power of 20 V, 1000 W. How can you find the amount of current used by the laptop? Identify such
static electrical device used and evaluate supply voltage taken by it. Which category does it belong based
on its ability to change voltage? Practical efficiency of such electrical device is less than 100 %. Justify
with reasons. What are possible ways to improve its efficiency?
- From the details mentioned in the problem, it is clear that the given device is the transformer.
In an ideal transformer, the power at the primary and the secondary side are equal.
The Current taken by the laptop is calculated by using the expression of power.
- The current used by the laptop is 40 A.
The supply voltage taken by it can be calculated as the power is balanced for the ideal transformer. The power at the secondary winding output will be equal to that on the primary winding output.
The voltage taken by the device is 250 Volts.
The given electromechanical device on the basis of its voltage changing capacity is transformer as the current on the secondary side is much higher than that on the primary side. Therefore it is a “step down transformer”.
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