Questions

This is a layer of atmosphere about 60 to 70 km above the earth and extends to about 400km. It contains ionised particles which can reflect radio waves making radio communication round the world possible.

No, since the structure contains a char pointer while writing the structure to the disk using fwrite() only the value stored in the pointer n would get written. When this structure is read back the address would be read back but it is quite unlikely that the desired string would be present at this address in memory

If for a short period of time circuits goes to some different logic level then it is spposed to have then it is called static hazard. e.g., If the final logic value of output of given circuit becomes one vent if if is supposed to be zero then it is called static-0 Hazard and vice versa. Dynamic Hazard is the one in which the circuit output goes to some other logic level more than once then finally settling down to some appropriate level.

AIDS: The term means Acquired Immunity Deficiency Synodrome. The virus attacks the T cells of the (white corpuscle type) blood and destroys them.

Pages are denoted as 

1 - 9 = 09

10 - 99 = 90*2 = 180

100 = 03

Hence, total number of digits = 09 + 180 + 03 = 192.