The similarity is that they both are types of bonds in molecules.
Ionic bonds are between a metal and a nonmetal.
Covalent bonds are between two nonmetals.
In fact, entropy of an isolated system never decreases (2nd law of thermodynamics), unless some external energy is provided in order to "restore" order in the system and decrease its entropy.
(note that when external energy is added to the system, it is no longer "isolated").
*This is only true if the question is referring to a certain system within the universe. If we are considering the universe itself as the system, then this option is no longer correct, because no external energy can be provided to the universe, and since the universe is an isolated system, its entropy can never decrease. If we are considering the universe itself as the system, none of the options is true.
In the context of the loop and junction rules for electrical circuits, a junction is where three or more wires are joined.
Answer: Option 2
<u>Explanation:
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An electrical circuits consists of many points like branch, loop, junction, series, bridge, etc. So, loops are the ones where the output of one circuit will act as feedback of the same circuit. If two or more wires passes through a single point, then that point is termed as junction.
If two or three junction connect each other they are termed as branch. Like these several other parameters are there with different rules in the circuit system. For electrical circuits, junction and loop rules state that a junction is the point where more wires joined together.
Explanation:
First consider that each hand works as a fulcrum: a pivot point where the barbell can rotate.
Now consider only the left hand. If the center of mass of the barbell is between hands (in the middle) it is displaced respect the fulcrum, therefore the weight which is pushing the bar downwards becomes a rotational force. The same thing happens to the other hand. Now, if more weight is added to the left hand the center of mass is displaced towards the left hand and depending how much weight is added, the center of mass will change its position and therefore the torque each hand experiences changes.
If the center of mass is still between hands: The torque remains almost the same changing only the magnitudes but not the direction.
If the center of mass is on the hand: there is no torque for the left hand because there is no leaver.
If the center of mass is to the left: now the torque changes direction and both hands need to stop it in the same direction.
(see diagram below)