In: Physics
Laptop computers are charged using laptop chargers (adapters) which are connected to 240 V supply and uses 1.5 A to provide 19 V to a computer. Describe in detail, how does adapter convert at 240 V supply to 19 V as output? Does this laptop adapter belong to step up or step down? Justify. What will be the output current if its efficiency is 96% ? The adapter uses low voltages like 240 V, 50 Hz whereas transmission lines operate at very high voltages. How it can be achieved? Inside the computer, A 50 Ω resistor and 100 μF capacitor are connected in series to a 50 Hz source. What will be the maximum voltage in the circuit if r.m.s current in the circuit is 0.3 A? Can you show that the sum of rms voltage across resistor and that across capacitor is more than rms voltage across entire circuit? Compare the phase angle for the above circuit with that for a circuit containing only capacitor.