Answer:
True.
Explanation:
A diode, which allows current to flow in one direction only, consists of two types of semiconductors joined together.
A semiconductor can be defined as a crystalline solid substance that has its conductivity lying between that of a metal and an insulator, due to the effects of temperature or an addition of an impurity. Semiconductors are classified into two main categories;
1. Extrinsic semiconductor.
2. Intrinsic semiconductor.
An intrinsic semiconductor is a crystalline solid substance that is in its purest form and having no impurities added to it. Examples of intrinsic semiconductor are Germanium and Silicon.
In an intrinsic semiconductor, the number of free electrons is equal to the number of holes. Also, in an intrinsic semiconductor the number of holes and free electrons is directly proportional to the temperature; as the temperature increases, the number of holes and free electrons increases and vice-versa.
In an intrinsic semiconductor, each free electrons (valence electrons) produces a covalent bond.
Humid air has higher pressure because of the heaviness of the water
Answer:
A cosmic year is 365.25 days, some times called a side real year and is just the time it takes for us to go round the sun once.
A light year is the distance light travels in a year. Now light travels at about 186,262 miles a Second! Which is not slow by any ones book.
An experiment was conducted just after Christmas a few years ago. Two girls were selected from the audience and went into two phone boxes a few feet apart. They could only hear each other via the phones. The phone call went to a ground station about 200 miles away, then up to a geostationary coms satellite, back to a ground station 1/3 of the way around the world, then repeated, with a third satellite before being sent from another ground station back to London and the other phone box. We the audience could hear both sides of the conversation from both boxes. And could hear the delay between sending and receiving. So even at the speed of light, there was about 1.5 seconds of delay. So because distances in space are so vast that saying a star is x millions of miles away causes problems, you run out of zero’s! So our nearest other star is about 4.5 light years away. Our sun (our nearest start) is about 8 light minuets away. Varies slightly as our orbit is not 100% cirular.
I HOPE THIS IS HELPFUL.
Answer:
From the previous explanation Student No. 1 has the correct explanation
Explanation:
When the fluorescent lamp emits a light it has the shape of its emission spectrum, this light collides with the atoms of Nitrogen and excites it, so these wavelengths disappear, lacking in the spectrum seen by the observed, for which we would see an absorption spectrum
The nitrogen that was exited after a short time is given away in its emission lines, in general there are many lines, so the excitation energy is divided between the different emission lines, which must be weak
From the previous explanation Student No. 1 has the correct explanation
Answer: having to push a rough and heavy box across the floor to move it
Explanation:
The Friction force is any force that is in opposite direction of the motion of an object or fluid due to the contact of this object or fluid with other bodies.
In this sense, there are different types of friction force thath are useful in different situations:
-The <u>Static friction force</u> prevents surfaces from slipping across each other. For example, the friction between your feet and the floor keeping you from slipping.
-The <u>kinetic friction force</u> as the force that helps the tires in a moving vehicle to slow down and stop when necessary.
However, if you want to push a heavy box across the floor to move it, the friction force will not be useful at all.
