answer
option d is the correct answer
explanation
as we know frequency is equal to 1 /t
f= 457 Hz
t=1
SO, 1/457
=0.0022sev
<span>a.The hiker had an easy, level trail from 11:00-12:00 and was able to travel the fastest during that time period.---> may be because this was indeed fastest stage
b.The hiker got tired and walked the slowest from 1:00-2:00.---> no, because this was not the slowest stage
c.The hiker stopped for lunch from 11:00-12:00 and that slowed him down.---> no because this was the fastest stage
d.The hiker ended up in the same place that he started.---> no, because the hiker walked more toward east than toward west and more toward south than toward north.
Answer: option a) </span>
<span>It is used to establish and maintain a proton gradient.</span>
Answer:A solenoid is a simple electromagnetic device consisting of a coiled electric wire, wrapped in a 3D circular pattern. When electric current is passed through the wire, the solenoid acts like a magnet with N and S poles at the ends of the coil.
When a ferromagnetic material rod is permanently placed inside the solenoid, the metal greatly increases the magnetic effect and becomes a permanent electromagnet. Moreover, it can also be used as an electrical switch by drawing in or pushing out a ferromagnetic material like an iron rod. Depending on the directions of the rod and the electrical current the switching action takes place.
Given figure represents the solenoid as electromagnet and the switching action.
Explanation: