Electrical Principles Coursework Example | Topics and Well Written Essays - 1250 words

Electrical Principles - Coursework Example It involves taking snapshot of each cell at installation time and then measuring subtle changes as cells age. A 25% resistance increase over the initial reading provides hints to the battery’s overall performance drop. Measurement of a battery’s internal resistance is done through reading voltage drop on load current or AC impedance. The obtained results are considered ohmic values. There is a widespread held notion that internal resistance has a relation to capacity, yet this is not true. Most batteries retain flat resistance throughout its service life. In figure 1 is the capacity fade and the internal resistance of battery cells. The circuit set-up contains the battery to be studied lying in series with a resistor. The potential difference across load is measured and so is the current for a different resistors/rheostat in the circuit. The idea is for the overall resistance of circuit changes so that the current is different each time. The reason that doing this is to tell us about internal resistance of battery because the potential difference across internal resistance is Vinternal resistance=I⋅r and it is possible to vary I by altering circuit resistance. Where the potential difference across internal resistance is varying and hence, we add up all potential differences given as E=Vload +Vinternalresistance in determination of internal resistance. This can be represented

Infant Short Term Memory and the Attention Span Essay

Infant Short Term Memory and the Attention Span - Essay Example The ability of carrying out various mental tasks consists of the use of cognitive functions. This developmental phase varies between infants in regard to whether they are full term infants or premature and also on what their short term memory capabilities are as well. Short-term memory in itself is a limited function even for adults, and infants in particular haven't quite mastered the skill of recalling events that happen in a short time frame (Cowan et al 1999, p. 1082). Nevertheless, in regards to attention span and some other cognitive abilities within infants, there appears to be a response to differentiating stimuli which shows that depending on what is used to gain their attention and maintain it varies from infant to infant. One study in particular was carried out on infants to gain an idea on what holds and keeps their attention span, with this one pertaining to what effects synchronized lighting has on infants (Colombo & Richman 2002, p. 475). This study showed that infants did pay attention to the timed lighting effect as their heart rate was found to increase in a pattern when the lights would flicker at specific times. This of course showed that even though infants aren't alert and wholly focused on every inanimate object that they come in contact with some of these various stimuli have a more profound affect than others. Furthermore, this one study was able to pinpoint the fact that infants seem to have the exact ability as adult people to be able to time exactly when a light simulation is going to take place, which shows that they are able to keep track of time when it is in regards to simulations of patterns. This in itself gives a positive idea of how important attention span is in infants as it is one of the key elements in contiguity learning within the early educational process (Colombo & Richman 2002, p. 477). In the past it was presumed that infants have a very short attention span but as more research has been carried out it is now being questioned just how short their attention really is. The reason this is stated is because, just like the previous test mentioned, this next study showed that babies might actually have the ability to distinguish characteristics of adding and subtracting, of course with a minute set of numbers (Wakeley et al 2000, p. 1525). When an infant is shown a display of a perceptual nature their attention span seems to be more focused, especially if the elements in the display are in the amount of three's, but no bigger amount than four. Research has shown that when cognitive researchers have added to the display or taken away the infants have been very alert to the actions and pay very close attention in what appears to be a detailed manner towards problem solving. This seemingly refutes the belief that infants attentions span is short as it is being shown that t his varies depending upon what the baby is being given to study and explore (Wakeley et al 2000, p. 1526). This type of study however did not give the same results for all infants that were included in it but even so, the majority of infants from the age range of 4 months to 9 months were very alert to the problem solving with innate objects and