Technology

Who invented the electric light bulb in 1879?

1879: Thomas Edison crowns 14 months of testing with an incandescent electric light bulb that lasts 13½ hours. Sir Humphry Davy had produced incandescent electric light in 1808 by passing battery current through a platinum wire. But the voltaic pile was expensive and could be messy.

How many volts should an alternator put out?

A car alternator needs to be putting out at least 13-14 volts (ideally between 13.8 and 14.2 volts) to effectively charge a 12 volt car battery. If the alternator is putting out too much voltage (15+ volts), it is likely your battery acid will boil over out of the battery.

Who invented the first typewriter?

The first typewriter to be commercially successful was invented in 1878 by Americans Christopher Latham Sholes, Frank Haven Hall, Carlos Glidden and Samuel W. Soule in Milwaukee, Wisconsin, although Sholes soon disowned the machine and refused to use, or even to recommend it.

Why are objects in the mirror closer?

Here’s a case for saying that objects in the mirror are closer than they appear: The mirror is slightly convex so as to give the driver a wider field of view. As a result, the expanse of mirror reflecting light from the object into my eye is smaller than the expanse would be if the mirror were flat.

How long did it take Michelangelo to sculpt ‘David’?

At the age of 26, Michelangelo began sculpting his monumental statue of David. He finished it seventeen months later, in January, 1504.

Can graphite conduct electricity?

Graphite is an electric conductor, consequently, useful in such applications as arc lamp electrodes. It can conduct electricity due to the vast electron delocalization within the carbon layers (a phenomenon called aromaticity). These valence electrons are free to move, so are able to conduct electricity.

What does the A stand for in am radio?

Note on the left that when the carrier wave of FM radio is modulated with sound that the distance between the waves, or the frequency of the carrier wave, changes. Thus, AM radio works by changing the amplitude of the carrier wave and FM radio works by changing the frequency of the carrier wave. Frequency Response.