How does the eye control the amount of light entering it?
2 answers:
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Answer:
The reactance of the capacitor
Explanation:
In an AC circuit containing different elements (capacitors, resistors and inductors), we cannot simply calculate the equivalent resistance of the circuit, so another quantity is used, which is called reactance.
For a capacitor, the reactance is given by:
where:
f is the frequency of the AC current in the circuit
C is the capacitance of the capacitor
The reactance has a similar meaning to that of the resistance for a DC current. In fact, we notice that:
- When f=0 (which means we are in regime of DC current, because the current never changes direction), the reactance is infinite. This is correct: in a DC circuit, the capacitor does not let current pass through it, so it like it has infinite resistance (=infinite reactance)
- When f tends to infinite, the reactance becomes zero: in such situation, the current in the circuit changes direction so quickly that the capacitor has no enough time to "block" the current in the circuit, so it like it has almost zero resistance (zero reactance).
At speeds over 30 mph, you should maintain a following distance of at least <u>three full seconds</u> behind the vehicle ahead of you.
As a general rule and common sense at a speed of 30 mph you can leave three full seconds so that you can achieve a prudent distance between the car you are driving and the car in front in order to be able to perform some kind of maneuver if an accident or unforeseen event occurs.
To count the full three seconds you can use the technique of counting the Mississippis as follows: Mississippi one, Mississippi two, Mississippi three.
<h3>What is an accident?</h3>An accident is an unexpected event that generally causes damage, injury or negative consequences.
Learn more about accident at: brainly.com/question/28070413
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