Analogue Circuits Question -- AC and DC currents through a coil

[IronaSona]

Summary:: .

Hi ,so am currently doing homework , and was wondering if anyone could tell me if i have done my calculations correctly ,because am not 100% sure that i have answer to those 2 questions correctly .If i have went somewhere wrong if you could tell me where and how i could fix it ,that would be great. Thank you.

 

[osilmag]

Your capacitive reactance answer looks good.

 

[Baluncore]

You are a bit more consistent than the examiner.
The questioner wrongly specifies lower case units, without a space; 100v, 250w, 50hz.

For units named after a person, such as Volta, Watt or Hertz;
the initial should be spaced and upper case; 100 V, 250 W, 50 Hz;
while the spelled out unit should be all lower case; 100 volt, 250 watt, 50 hertz.

 

[Delta2]

Both answers contain typos.
The answer for the capacitor case looks ok, though I haven't check the arithmetic operations.

The answer for the coil contains too many typos and inconsistencies, for example you write that $Z=\sqrt{R^2+X_L^2}$ and then later you seem to imply that $Z=X_L$.

Please rewrite the answer for the coil.

 

[IronaSona]

Both answers contain typos.
The answer for the capacitor case looks ok, though I haven't check the arithmetic operations.

The answer for the coil contains too many typos and inconsistencies, for example you write that $Z=\sqrt{R^2+X_L^2}$ and then later you seem to imply that $Z=X_L$.

Please rewrite the answer for the coil.

is this better ?

 

[Delta2]

Nope you basically do the same mistake. The correct way to go is as follows:
The coil's impedance at 60hz is $Z=\frac{140}{2}$. Use this and the equation $Z=\sqrt{R^2+X_L^2}$ to correctly determine the reactance $X_L$ at 60 hz and from that the value of L.
Then you should NOT forget the ohmic resistance of the coil when you calculate the new reactance and new impedance at 50hz

 

[IronaSona]

Nope you basically do the same mistake. The correct way to go is as follows:
The coil's impedance at 60hz is $Z=\frac{140}{2}$. Use this and the equation $Z=\sqrt{R^2+X_L^2}$ to correctly determine the reactance $X_L$ at 60 hz and from that the value of L.
Then you should NOT forget the ohmic resistance of the coil when you calculate the new reactance and new impedance at 50hz

 

[Delta2]

There are still some typos but now what you do seems correct. Havent checked the arithmetic.