Recent content by cgiustini

My simplistic derivation below for a Class A amplifier shows that an AC signal at the input produces DC, fundamental, and 2nd harmonic terms at the output. This seems to contradict most the information I have found on this - which just states that the output is sinusoidal and of the same...

Hi, Thank you for looking in this. I found an additional text here...

Hello, I'm reading through section 6.2.2 of https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-013-electromagnetics-and-applications-spring-2009/readings/MIT6_013S09_chap06.pdf on page 157. I understand all the math, but I have a conceptual questions that I don't seem to...

Hi, I'm looking at the following graph, but there are a few things I don't get. For instance: curl should always be zero in circles where the field lines are totally straight (right-most figure) curl should always be non-zero in circles where the field lines are rotating (center figure in 2nd...

Thanks for the replies. I appreciate it. From Faraday's Law, I understand mathematically that increasing L reduces the rate of change of current through an inductor. What I'm trying to understand is the qualitative behavior behind this. vanhees71, your response states that a changing current...

Hi, I have a qualitative question about RL circuits. I'm trying to summarize how R and L each affect the transient response time L/R from the perspective of energy transfers. I'm pretty confident in my description of the influence of L. I'm not very confident in my description of R in the case...

Thanks for both of your answers. I think I agree more with gmax137. I think that the energy is most likely dissipated as heat (potential friction in the elbow joints), but I don't know enough about the body to be certain. But why couldn't there be other bodily mechanisms that dissipate the...

When one lifts a block off of the ground and holds it in the air, the work done by one's lifting force is equal to the change in total mechanical energy of the block/earth system. Since the mechanical energy is KE+PE and since KE doesn't change during the motion, the work done by the lifting...

Yea, it doesn't make sense to think that the potential energy is converted from kinetic energy that is created in some intermediate step. While the ball moves up, the increase in kinetic energy of the system is equal to the net work on the ball. The net work on the ball is the sum of the...

Thanks for the response. Statement 2 doesn't mean that any kinetic energy gets created while the ball gets lifted up. In statement 2, I mean that the earth/ball system is siphoning the kinetic energy from the ball and turning it in potential energy during the movement. Through every...

Hi, I'm trying to formulate some general ideas on how systems convert energy imparted by external forces. Could anyone please read the following and see if any of the statements and examples are correct? I really like the idea of thinking of isolated systems as "machines" through which energy...