Question

q-3,5 and 7 please answer fast .........​

Answer 1

3)Only one triad of dobereiner's triads exist in the columns of Newland's octaves. The triad foemed by the elements Li, Na and K of Dobereiner's triads also occurred in the columns of Newland's octaves.

5)It is due to the transmission of electricity which is more efficient which transports coal or oil over the same distance. On the other hand hydro power plant will convert the potential energy of falling water into the part of the electricity.

7)The resistance of a conductor is directly propotional to the lenght of the conductor. The resistance of the metallic wire, when it is cut into ten parts of equal length is r=R/10.

Two such pieces when joined in series, the equivalent resistance of these two parts = r+r=2r=2R/10

Seriea resistance of two parts=2R/10=R/5,

5 such elements are connected in parallel. Therefore, the total resistance R' will be 1/R'=R/25.