A capacitor is useful in?

Question

A. boosting the energy output of a circuit
B. increasing the current in a resistor
C. smoothing pulsed current
D. switching dc to ac in a circuit
E. increasing or decreasing voltage

Answer 1

C. Smoothing pulsed current.

Dr. H

Answer 2

C. smoothing pulsed current

not B. current in resistor is dependent on voltage not cap.
not D. the switching is done by rectifiers. The cap only smooths the output.
not E. but a tricky one because when a cap is part of an integrator circuit it can reduce peak voltage (or increase in a differentiator) . However, this only affects AC.
not A. trickier still, since a cap can store energy. A cap. can store energy from low-level power source over a long period of time and release it very quickly creating the appearance of increased energy output but in reality the energy out is the same as the energy in (no net gain).

Answer 3

C, as the pulse is present it producing a charge in the capacitator, and the load draws current from the system.
As the pulse is not present, and the load continues to draw, the energy stored in the capacitator decreases and it produces a current to the load. Therefore, it tried to maintain a voltage by generating current.

Another way of thinking of the capacitator is : It resist change, this can be seen as a change in voltage will cause it to adjust the current to maintain this voltage.
Therefore, as the voltage drops it will return energy to the circuit to produce current to maintain this voltage.
This is how it can be used as a filter to reduce the ripples of rising & falling current levels in a pulsing type circuit.

Answer 4

It's not A, B, or D. Depending on its exact purpose, it could provide a voltage if the voltage source was turned off.

But it can serve as a filter and smooth pulsed current. The way it works is that it fills up with charge and then will release charge slowly, so think of it as a buffer system.

In other words, the correct answer to your HW problem is C.

Answer 5

"A" A capacitor stores current until it builds up and instantly discharges at a higher voltage. Electronic flash on camera is an example, you hear the whine as the capacitor charges and when you push the flash button, the high stored charge is released.

Answer 6

C. . . . .it acts as a stabilizer. . . .it doesn't allow excess voltage to pass through. . . .

Answer 7

c

Answer 8

E. im pretty sure