Related Concept Videos

Sound Intensity Level00:53

Sound Intensity Level

Humans perceive sound by hearing. The human ear helps sound waves reach the brain, which then interprets the waves and creates the perception of hearing. The loudness of the environment in which a person is located determines whether they can distinguish between different sound sources.
The human ear can perceive an extensive range of sound intensity, necessitating the use of the logarithmic scale to define a physical quantity—the intensity level. It is a ratio of two intensities and hence a...
Special considerations while measuring pulse01:13

Special considerations while measuring pulse

Assessing a patient's pulse is a fundamental skill in healthcare, but certain situations require special attention:
Insulation Coordination01:23

Insulation Coordination

Insulation coordination is the process of matching electric equipment's insulation strength with protective device characteristics to protect the equipment against expected overvoltages. This selection is based on engineering judgment and cost. Equipment can generally withstand short-duration high transient overvoltages, but repeated tests with identical waveforms can yield inconsistent results. As a result, standard impulse voltage waveforms are used for testing, defined by specific times for...
Impulse Response01:17

Impulse Response

The impulse response is the system's reaction to an input impulse. In an RC circuit, the voltage source is the input, and the capacitor's voltage is the output. The system's state and output response before and after input excitation are distinctly defined.
Kirchhoff's law forms an input signal equation, with the capacitor's current and voltage providing the output. Substituting the current and dividing by RC yields a differential equation. The output for an impulse input is the impulse...
Series R—L Circuit Transients01:22

Series R—L Circuit Transients

In a series resistor-inductor (R-L) circuit, closing the switch at the start of the time period simulates a three-phase short circuit, a fault condition where all three phases of an unloaded synchronous machine are short-circuited. When there is no fault impedance and no initial current, the initial voltage is determined by the phase angle of the source voltage.
Using Kirchhoff's Voltage Law (KVL) to analyze this circuit helps determine the total asymmetrical fault current, which consists of...
Line Protection with Impedance Relays01:27

Line Protection with Impedance Relays

Coordinating time-delay overcurrent relays in complex radial systems and directional overcurrent relays in multi-source transmission loops can be challenging. Impedance relays address these issues by responding to the voltage-to-current ratio, specifically measuring the apparent impedance of a line. These relays become more sensitive during faults as current increases and voltage decreases, thereby reducing the apparent impedance.
Under normal conditions, low load currents keep the measured...