117. What was the active medium used in the first working laser ever constructed?

A. A diamond block
B. Helium-neon gas
C. A ruby rod
D. Carbon dioxide gas
✅ The correct answer is option C.
Theodore Maiman built the first working laser using a ruby rod while working at Hughes Research Laboratories in Malibu, California. It lased for the first time on May 16, 1960.

118. In 1983, which person was the first to offer a definition of the term ‘computer virus’?

A. McAfee
B. Smith
C. Cohen
D. Norton
✅ The correct answer is option C.
1983 Fred Cohen, while working on his dissertation, formally defines a computer virus as ‘a computer program that can affect other computer programs by modifying them in such a way as to include a (possibly evolved)copy of itself.’