The step-down transformer gives a current of 10a at 24v if the primary voltage is 240v calculate the 1_primary current 2_the power input 3_the power output

You probably do this as a DC circuit which is not quite correct, but it will get you an answer. The study is a great deal more complicated.

Problem One: Secondary Power.

W = E * I

E = 10 A

I = 24V

W = 24 * 10

W = 240 Watts.

Here's the thing you have to know. These transformers are 100% efficient (or are assumed so). So whatever wattage is in the secondary, it is the same as that in the primary.

Primary Power = Secondary Power

Secondary Power = 240 Watts

Primary Power = 240 Watts

W = E * I

E = 240 volts

W = 240 watts

I = W/E = 240 / 240

I = 1 Amp. Answer Part One

Part Two

Answered above. 240 watts.

Part Three

Answered above. 240 watts.

Secondar

its c i just checked it