Options are not given in the question. The complete question is as follows:
Read the following statements carefully: X: It is a thick black coloured liquid which is obtained from coal.Y: It was used earlier in railway engines to produce steam to run trains.Z : It is used to run heavy vehicles such as buses, trucks, tractors, etc.X, Y and Z respectively are
A. a. Coal tar b. Coal c. Diesel
B. a. Coal b. Paraffin wax c. Petrol
C. a. Coke b. Coal tar c. Kerosene
D. a. Coke b. Coal c. Coal tar
Answer:
A. a. Coal tar b. Coal c. Diesel
Step-by-step explanation:
Coal Tar is a thick black or dark brown colored liquid obtained from coal. Coal Tar consists of hydrocarbons and free carbon extracted from coal using a process of destructive distillation. So, X is coal tar.
Earlier coal was used to produce steam to run steam engine trains. Air flows are allowed to burn coal hotter, then the hot coal turns water to steam and helps in the locomotive steam engine to run. So, Y is coal.
Deisel is used to run heavy vehicles such as buses, trucks, tractors, etc. because diesel burns at slow speed and produces a higher torque that can move heavy automobiles. So, Z is deisel.
Hence, the correct option is A.