50/200×100%=25% is answer the formula is usefull energy output divided by total energy provided into 100%
The medium is the component of communication through which information is transferred. The correct option in the given question is option "c". Medium is actually the means through which communication is done. It can be a an oral message or written message or it can be nonverbal or symbolic. Any kind of message transmission requires a medium and without an medium no message can be transmitted. Whenever people talk on the telephone or write a letter, there has to be a medium for transmitting the message to the person on the other side.
If you go to the right along the periodic table, electronegativity increases.
So the larger the column number, the greater the electronegativity.
-Lithium has lowest as it is in the 1st column
-Beryllium (2nd column)
-Boron s (13th column)
-Nitrogen (15th column)