Oscillations of electricity and magnetism create ________________________ waves, which include visible light waves.
1 answer:
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Answer:
D. shortest wavelength
Explanation:
Photons with the highest energy have the shortest wavelength. The shorter the wavelength, the higher the energy of a photon.
A photon is a quantity that transmits electromagnetic energy from one place to the other.
- Gamma rays have photons that transmits the highest amount of energy.
- The rays have the shortest wavelength and highest frequency of all electromagnetic radiations.
Energy, wavelength and frequency of a photon are connected using the expression:
E = h f =
E is the energy
h is the Planck's constant
f is the frequency.
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).