Answer:early models of telephones were used with a twirl of numbers
Explanation:
Not advanced technology
Answer:
c) parallel to the wire
Explanation:
The concept is based on right-hand thumb rule that states that the thumb points in the direction of the current and the fingers will represent the direction of the lines of magnetic force.
As the current is moving in the east-west direction. Using the right-hand thumb rule, the direction of the magnetic field at a point below the wire is from north to south. So, when viewed from the west end, the magnetic field at a point will be anti- clockwise.
Hence, the correct answer is "b) anti- clockwise".
Answer:
A. The top layer will be diethyl ether, and the top layer will be yellow.
Explanation:
The purpose of the addition of the saturated aqueous solution of polar solvents like sodium chloride in the liquid-liquid extraction techniques is to remove as well as separate any kind of water which may be dissolved in the ether. Water and sodium chloride are both polar and thus, they forms the bottom layer and only ether forms the top layer. The compound being organic and is colored is in the top layer with the ether.
Hence, answer - A. The top layer will be diethyl ether, and the top layer will be yellow.
Answer:

Explanation:
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In this case, since perchloric acid is HClO4 and is a strong acid and calcium hypochlorite is Ca(ClO)2, the undergoing molecular chemical reaction turns out:

Thus, since the resulting hypochlorous acid is weak, it does not fully ionize, so it remains unionized, however, we can write the ions for the other species:

Now, we can cancel out the spectator ions, calcium and perchlorate, to obtain:

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The five main branches of chemistry are organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry and biochemistry. Chemistry can be further divided into many sub-branches that may fall under more than one of the main branches.