The Wireless Museum has several of the earliest crystal wireless sets from the 1920s which ran on electromagnetic waves with no external power source, and were easily made at home. Valve radios, which came along in the 1930s, needed electricity to heat up the valves and the museum has both mains and battery-powered valve radios on display. The collection also has some rare wartime civilian receivers — the only type of valve radio manufactured during the Second World War. This was by order of the government, because at this time most manufacturing was focused on the war effort. There are also plenty of modern day transistor radios including a collection of novelty radios dating from the sixties and seventies.
It is pointed out in the passage that, during World War II, _____.
transistor radios began to replace traditional valve radios
the production of wireless sets was almost entirely for military purposes
various types of radios requiring no external power source were developed
the government banned all kinds of civilian receivers
the efficiency of valve radios was upgraded through the introduction of new designs
We learn from the passage that the very early crystal wireless sets _____.
were the models out of which transistor radios were later developed
were manufactured in large quantities before the arrival of valve radios
are among the museum’s most precious exhibits
were still in use during World War II, though in limited numbers
were unconnected to an outside power system
It is clear from the passage that valve radios ____.
were still in widespread use in the sixties and seventies
originally operated on electromagnetic waves
consumed more electricity than one might expect
are of two types: mains and battery-powered
were costly products and the government disapproved of them
This passage is concerned with ____.
the exhibits of a wireless museum which cover a considerable variety
the government’s war efforts and production policies regarding radios