BPSC – Combined Competitive Examination · প্রশ্ন 10
In the context of lab-grown diamonds (LGDs), what is used as the starting carbon material ('seed')?
উত্তর দেখান ও ব্যাখ্যা
উত্তর: (C) Graphite
ব্যাখ্যা
Lab-grown diamonds must start from carbon; in the HPHT method graphite is the carbon source (CVD uses a thin diamond seed plate with methane).
- (A) ভুল
Wrong: aluminium oxide; contains no carbon.
- (B) ভুল
Wrong: silicon carbide; a diamond simulant.
- (C) সঠিক
Correct: graphite, a form of carbon, is converted to diamond under high pressure and temperature.
- (D) ভুল
Wrong: zirconium dioxide; a diamond simulant.