Question

1a. Computers that predated the transistor (such as the ENIAC) used what technology to implement binary logic?

1b. How many electons does each of the following elements have?

silicon

boron

phosphorus

1c. A diode has how many terminals and how many junctions ?

A transistor has how many terminals and how many junctions?

Answer 1

1 a)yes,we know that computer exists even before of the discovery of transistor. So how those computers managed with the binary logic? The answer is very simple.

vacuum tubes,these things are are used for implementing a logic system in a traditional computer. But the size of the system looks likely a larger room. They vacuum tubes are look like a bulb and this elements are not using nowadays.

How a vacuum tube work? The general working theory of this elements is thermionic emission. That is when we heat a metal it will loose electrons and this was the main logic and used as a switch or amplifier. These computers are also known as first generation computers.

1 b)

Silicon - silicon have 14 electrons. And electron configuration is 2,8,4.

Boron-boron have 5 electrons and electron configuration was 2,3.

Phosphorus - phosphorus have 15 electrons and the electron configuration was 2,8,5.

1 c)

A diode is setup with semiconductors and have 2 terminals called anode and cathode. The working of diode is in a diode the current will flow through only one direction. And the making of diode is combining a n type semiconductor with a p type semiconductor. So it have only 1 Junction called pn Junction (depletion region).

A transistor is also a semiconductor device and created by combining 2 diodes back to back. It have 3 terminals and which are from emmitor, base and collector leyers of the transistor.

• Emmitor - this is the majority charge carrier and will be moderately doped and will be moderate in size.
• Base-this is the middle section of the transistor and will be lightly doped and will be large in size.
• Collector - this will gain the charge supplied by the emmitor and will be larger in size, also collector will be heavily doped.

And a transistor have 2 junctions named pn Junction. Based on the connection type transistor was categorized into two called npn and pnp transistor.

• npn-

• pnp-