Question

The plug-in transformer for a laptop computer puts out 7.50 V and can supply a maxiμm current of 1.8 A. Randomized variables i

a) Voltage and current
b) Resistance and power
c) Impedance and capacitance
d) Inductance and frequency

Answer 1

The maximum input current of a transformer for a laptop, with a 240 V input and output of 7.50 V at 2.00 A, assuming 100% efficiency, is 0.0625 A or 62.5 mA. If efficiency decreases, the input current would increase.

Step-by-step explanation:

The question revolves around the operation of a transformer for a laptop computer, which is a device used to convert one voltage to another. Let's address 48 (a) first. If the transformer supplies 7.50 V and is capable of delivering a maximum current of 2.00 A, and the input voltage is 240 V, we can use the principle of conservation of energy (power input = power output for 100% efficiency) to find the maximum input current:

Power output = Voltage output × Current output
Power output = 7.50 V × 2.00 A
Power output = 15.0 W

Since the efficiency is assumed to be 100%, this will also be the power input.

Power input = Voltage input × Current input
Current input = Power input / Voltage input
Current input = 15.0 W / 240 V
Current input = 0.0625 A or 62.5 mA

Next, for 48 (b), if the actual efficiency is lower than 100%, the input current would need to be greater than 62.5 mA to compensate for the energy losses in the transformer.