ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: GuessWho on June 04, 2011, 09:52:47 pm
-
I recently came across a question in the Insight 2009 Physics exam.
The question was:
Which one of the following statements best describes the method to reduce the ripple voltage, Vr?
A. Increase the time constant, τ, of the capacitor–load resistance circuit.
B. Increase the capacitance of the capacitor and decrease the resistance of R1.
C. Decrease the capacitance of the capacitor and increase the resistance of R1.
D. Decrease both the resistance R1 and the capacitance of the capacitor.
The answer says:
Ripple voltage, Vr = Vmax*T/RC . Therefore, the ripple voltage will reduce if RC reduces.
Am I missing something or are the answers wrong?
If RC were to reduce wouldn't that cause an increase in Ripple Voltage?
-
Decreasing the denominator (RC) will increase the ripple voltage and not decrease so i think you are right, increasing RC will decrease ripple voltage because the signal will be smoothed more with the greater time constant. so the answer should be A), unless i have missed something aswell.
-
I recently came across a question in the Insight 2009 Physics exam.
The question was:
Which one of the following statements best describes the method to reduce the ripple voltage, Vr?
A. Increase the time constant, τ, of the capacitor–load resistance circuit.
B. Increase the capacitance of the capacitor and decrease the resistance of R1.
C. Decrease the capacitance of the capacitor and increase the resistance of R1.
D. Decrease both the resistance R1 and the capacitance of the capacitor.
The answer says:
Ripple voltage, Vr = Vmax*T/RC . Therefore, the ripple voltage will reduce if RC reduces.
Am I missing something or are the answers wrong?
If RC were to reduce wouldn't that cause an increase in Ripple Voltage?
The ripple voltage will be reduced if RC is increased actually. So I'd say the answers are incorrect. B,C,D will all increase the amount of ripple, so A would be the best answer out of all of them.
-
Woah. what is ripple voltage?
-
Ripple voltage (further electronics section) is the Vout max-min values of a smoothed recitifed circuit. Also given by the formula GuessWho mentioned Vr = Vmax*T/RC.
-
Lol don't worry about ripple voltage unless Further Electronics is your detailed study. To be honest I'd rather be doing Einstein's relativity but my school only teaches further electronics unfortunately.
-
Oh, jesus.. as soon as I saw "don't worry about ripple voltage unless Further Electronics is your detailed study" my jaw reattached :/
-
I actually just did this practice exam (didn't realise you said it WAS insight 2009, haha), almost flipped when I saw the wrong answer on literally the second last question (I was 100% up until then) but then I'm pretty sure that answer is wrong, and I'm right. (A)
-
I actually just did this practice exam (didn't realise you said it WAS insight 2009, haha), almost flipped when I saw the wrong answer on literally the second last question (I was 100% up until then) but then I'm pretty sure that answer is wrong, and I'm right. (A)
Yea I was the same. I was just like, you can't be serious..., I screwed up an easy question like that?!.