Step 1: Understanding what charcoal is
Charcoal is a lightweight black carbon residue that is produced by strongly heating wood or other organic materials in minimal oxygen.
Step 2: Usage in drawing and art
In art, "charcoal" refers to a dry medium made from finely ground organic materials that are held together by a gum or wax binder.
It is widely used for sketching, shading, and fine art work.
Step 3: Is charcoal the same as graphite?
While not exactly the same chemically, both graphite and charcoal are forms of carbon.
Charcoal is closer in texture and appearance to graphite and is used similarly in artistic applications.
Step 4: Evaluating options
(A) Graphite $\Rightarrow$ Correct. Charcoal is a form of carbon and closely resembles graphite in function.
(B) Red colour $\Rightarrow$ Incorrect. Charcoal is not a pigment colour like red.
(C) Oil colour $\Rightarrow$ Incorrect. Oil colours are oil-based pigments, whereas charcoal is dry and powdery.
(D) None of these $\Rightarrow$ Incorrect. (A) is correct.
\[
\boxed{\text{Correct Answer: (A) Graphite}}
\]
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.