Electrical resistance
Voltage can be thought of as the pressure pushing charges along a conductor, while the electrical resistance of a conductor is a measure of how difficult it is to push the charges along. Using the flow analogy, electrical resistance
Capcharge
The product of the resistance and capacitance, RC, in the circuit is known as the time constant. This is a measure of how fast the capacitor will charge or discharge. After charging a capacitor with a battery, the battery can be removed and the
Voltmeters
Resistors in parallel have the same voltage across them, so if you want to measure the voltage across a circuit element like a resistor, you place the voltmeter in parallel with the resistor. The voltmeter is shown in the circuit diagram as a V
An excellent way to check your answer is to go back and label the voltage at each point in the circuit. If everything is consistent,your answer is fine. To label the voltage, the simplest thing to do is choose one point to be zero volts. It's just the dif
If we applied the junction rule at junction b, we'd get the same equation. So, applying the junction rule at one of the junctions is allwe need to do. In some cases you will need to get equations from more than one junction, but you'll never need to get a
Capacitors: devices for storing charge
A capacitor is a device for storing charge. It is usually made up of two plates separated by a thin insulating material known as the dielectric. One plate of the capacitor is positively charged, while the other has n
Energy stored in a capacitor
The energy stored in a capacitor is the same as the work needed to build up the charge on the plates. As the charge increases, the harder it is to add more. Potential energy is the charge multiplied by the potential, and as th
Electric fields and potentials in the human body
The body is full of electrical impulses, and we can measure these signals using electrodes placed on the skin. The rhythmic contractions of the heart, for example, are caused by carefully timed electrical i
The branch current method
To analyze a circuit using the branch-current method involves three steps: 1. Label the current and the current direction in each branch. Sometimes it's hard to tell which is the correct direction for the current in a particular
Multi-loop Circuits and Kirchoff's Rules
Before talking about what a multi-loop circuit is, it is helpful to define two terms, junction and branch. junction is a point where at least three circuit paths meet. branch is a path connecting two junctions.
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