Home › JEE Main › Physics › Semiconductor Devices › Before 1948, electronic devices were mostly vacu…
Before 1948, electronic devices were mostly vacuum tubes. What was discovered that year?
AThe transistor
BThe vacuum diode
CThe triode valve
DThe pentode valve
Answer & Solution
Correct answer: A. The transistor
1. Vacuum tubes ruled until a solid-state device arrived.
2. That device controls current inside a solid.
3. It was the transistor, in 1948.
_Source: NCERT Class 12 Physics Part II, Chapter 14, Semiconductor Electronics._
Related questions
The function of a logic gate is defined by its:The five common logic gates are NOT, AND, OR, NAND and:An LED converts electrical energy into:Photodiodes, LEDs and solar cells are together called:A full-wave rectifier built with two diodes needs a transformer with a:Under forward bias the depletion layer:A p-n junction with metal contacts at its ends is a:Despite extra carriers, a doped crystal as a whole is: