Reading Caplan in Karachi

Farhat Moazam1

  • 1Professor and Chairperson, Center of Biomedical Ethics and Culture, Sindh Institute of Urology and Transplantation, Dewan Farooq Medical Complex, Karachi, 74200, Pakistan., famoz@mindspring.com.

Related Concept Videos

Capacitors and Capacitance01:18

Capacitors and Capacitance

A device consisting of two electrical conductors that are separated by a distance and used to store electrical charges is called a capacitor. The space between the conductors is either a vacuum or an insulating material, called a dielectric. Capacitors have many applications, ranging from filtering static from radio reception to energy storage in heart defibrillators.
When the conductors are two identical parallel plates, it is called a parallel plate capacitor. When battery terminals are...
RC Circuits: Charging A Capacitor01:30

RC Circuits: Charging A Capacitor

A circuit containing resistance and capacitance is called an RC circuit. A capacitor is an electrical component that stores electric charge by storing energy in an electric field. Consider a simple RC circuit having a DC (direct current) voltage source ε, a resistor R, a capacitor C, and a two-way position switch. In the circuit, the capacitor can be charged or discharged depending on the position of the switch.
When the switch is moved to connect the battery, the circuit reduces to a simple...
RC Circuits: Discharging A Capacitor01:27

RC Circuits: Discharging A Capacitor

One of the applications of an RC circuit is the relaxation oscillator. The relaxation oscillator comprises a voltage source, a capacitor, a resistor, and a neon lamp. The lamp acts like an open circuit (infinite resistance) until the potential difference across the neon lamp reaches a specific voltage. At that voltage, the lamp acts like a short circuit (zero resistance), and the capacitor discharges through the neon lamp and produces light. Once the capacitor is fully discharged through the...
Capacitor in an AC Circuit01:23

Capacitor in an AC Circuit

A capacitor is charged by passing an electric current through it, which causes the plates to start accumulating an electrostatic charge. Since the strength of the charging current is maximum when the capacitor plates are uncharged and gradually decreases exponentially until the capacitor is fully charged, the charging process is neither instantaneous nor linear. The property of a capacitor to store a charge on its plates is called its capacitance.
Consider a purely capacitive circuit consisting...
Capacitors01:15

Capacitors

Capacitors play a crucial role in car radios, where they filter and store frequencies to ensure clear signal reception. Essentially serving as energy storage devices, capacitors store energy within their electric field and are composed of two parallel conducting plates separated by a dielectric.
When a voltage source is connected to a capacitor, positive and negative charges accumulate on the opposite plates. This accumulation generates a potential difference that equals the product of the...
Series and Parallel Capacitors01:14

Series and Parallel Capacitors

Capacitors, fundamental components in electronic circuits, can be connected in series and/or parallel configurations. Each configuration has different impacts on the overall behavior of the circuit.
First, consider capacitors connected in series to a battery. In this configuration, the plate connected to the battery's positive terminal develops a positive charge, while the plate attached to the negative terminal becomes negatively charged. An equal magnitude of charge is induced on the other...