Search Results

The equation for a resistor current versus voltage is not time-dependent, but the equations for capacitors and inductors contain time derivative and time integrals, So, a network of those components requires …

The presence of a parallel-plate capacitor means that in part of the circuit (only a small part; capacitors rarely have a gap as large as one millimeter) there is no movement of electrons, only a bu …

If a conductor with one end grounded has voltage source applied to its other end, or has a current source connected to it, the resistance of that conductor does relate the current and voltage according … the law of Ohm just means equivalence and that voltage is not the cause Yes, that seems correct. Does generator voltage drive a resistive light bulb, or generated current? …

The low power drawn corresponds to low current on the input side (assuming an AC voltage source is pressent), which is just the transformer impedance equation being obeyed. …

I think the intent of that statement is that the current in the secondary windings, if there's a good current-carrying load present on the secondary terminals, acts in the opposite sign to the primary …

What physically determines voltage, is electric field. … To be correct, any scalar field that has the right gradient would be acceptible, and that means one can add an arbitrary constant to each point of any voltage field; a constant field has zero gradient, …

Ohm's law is (approximately) true for a variety of current-carriers, and always (because of thermodynamics) is expected to have a positive current in a positive field (voltage drop), reflecting the fact … That's another reason that more voltage generally means more current: no parts of the system have negative resistance except in a local-small-fluctuation in the flow (like an eddy in a stream might include …

Resistance, by definition, is a voltage divided by a current. … So, a series of resistors has a terminal voltage which is the sum of the voltage drops of the individual resistors, and (because the resistors are in series) an operating current which is identical for …

When a switch opens, a current drops to zero, but not a voltage. The voltage across the switch is known to be zero only when the switch is closed. … Now, the voltage on the secondary drops as the current flows in the direction that demagnetizes that iron core, and when there's no longer enough voltage to keep the gap filled with ionized (conducting …

In a sense, all charges are measured by sampling the field (i.e. voltage gradient) they create. … It cannot, however, be identified with a particular voltage value, unless 'infinity' were such a value. …

[about a bar magnet inducing current in a solenoid as it passes through, axially] The magnet both has a north pole, and a south pole. At the center of the solenoid, the symmetry of the situation me …

Similarly, the electrical potential on two terminals of the device-under-test must be connected to a voltmeter in order to determine the potential difference, the voltage. …

What is different, is the proportional relationship between stored energy per unit charge (voltage) and amount of charge (ampere-seconds) stored. … The important thing is, pulling B away from A doesn't change the charge on B: it only changes the capacitance, i.e. the charge divided by the voltage. So, the voltage rises. …