You can't see any of them, but there may literally be millions.
4
on the order of a billion
4billion
Yes it is!
A modern micro processor has atleast 100 million transistors. The Core i7 920 (D0 stepping) has approximately 781 million transistors.
As of the end of 2016, high end multicore microprocessors have from 3,000,000,000 to 8,000,000,000 transistors. But there are plenty of other medium range microprocessors and microcontrollers with much fewer transistors being manufactured.
The CPU is housed on a silicon chip that contains millions of switches and circuits. It has millions of Transistors
Moore's Law. And it's actually 12 months, now. But yes, the original theory was that the overall number of transistors on a CPU die would double every year and a half. The correction to Moore's Law is influenced, among other things, also by the reduction in size of the dies and the transistors themselves.
Yes, today's computers use transistors and microprocessors. Smaller transistors subset the amount of RAM that is local to the CPU at any given moment.
Size, power, cost, and speed... The size of a CPU with individual transistors could easily require a room full of electronics, whereas a modern CPU chip is smaller than a small coin. The power of a CPU with individual transistors could easily be in the kilowatt or hundreds of kilowatts range, requiring specialized power systems, whereas a modern CPU chip only requires 25 to 100 watts per core. (At full load.) The cost of a CPU with individual transistors could easily be in the millions of dollars, whereas the modern CPU chip might only be a few hundred dollars. The speed of a CPU with individual transistors is limited by the length of the conductors. The speed of light is about one foot per nanosecond. (3 x 108 m/s divided by 1 x 109 ns/s) If you have a large, room size CPU, there are physical limits on how fast it can go. A modern CPU chip can easily run in the GHz range, an impossible feat for a room sized CPU.
A CPU works off of DC voltage. If you monitor the current draw of a CPU, it will likely not be DC, since a modern CPU is a CMOS design, current is only drawn when transistors are switched (ignoring the small leakage current). This is why overclocking (forcing the transistors to switch faster) can cause the CPU to overheat, and why "power save" mode on a laptop sometimes slows down the processor speed.
essentially a switch controlled by an electrical current
It refers to the 14 nm transistors with haswell architecture