Question

The question has statement - 1 and statement - 2 Of the four choices given after the statements , choose the one that best describes the two statements
statement - 1 : Sky wave signals are used for long distance radio communication . These signals are in generel , less stable then ground wave signals
statement - 2 : The state of inosphere varies from to hour day and season to season .
A. Statement-1 is true: Statement-2 is true, and Statement-2 is correct explanation of Statement-1.
B. Statement-1 is true, Statement-2 is true, but Sttement-2 is not a correct explanation of Statement-1.
C. Statement-1 is true, but Statement-2 is false.
D. Statement-1 is false, but Statement-2 is true.

Answer 1

Since the ionospheric properties change with time and season hence sky wave signals are in general less stable than ground wave signals. Thus statement-2 is correct and is a correct explanation of statement-1.