Science and Nature Quiz for 19 April 2023

A new science quiz is available each week. Try our daily general knowledge quiz or work through our archive of daily and themed quizzes.

Question 1: What is a specialized linear-beam vacuum tube used as amplifiers at microwave and radio frequencies to produce both low-power reference signals for superheterodyne radar receivers and to produce high-power carrier waves for communications and the driving force for modern particle accelerators?