MC chapter 16
Terms
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- When the number of electrons and portons in a sample of matter are equal, the matter is:
- neutral
- Rubbing one substance against another causes:
- a transfer of electrons.
- Two positively chrged pith balls, brought close together:
- repel each other
- An electroscope contains two thin pieces of metal foil called:
- leaves
- In a cloud, the rubbing of water droplets against air molecules produces:
- static electricity
- A bolt of lightning is seen because:
- the electrons ionize the air.
- In an electric current, electrons generally flow:
- from a point of excess to a point of deficiency.
- An example of an insulator is:
- rubber
- Insulators:
- can hold a static charge
- The first steady flow of electric current by checmical means was produced by:
- Volta
- Two strips of different metals, placed in a liquid electrolyte, consititue:
- a voltaic cell.
- In a voltaic cell, an electrode that has a deficiency of electrons is called the:
- cathode
- A convenient, portable source of electric current is a:
- dry cell
- The outer casting of a dry cell is generally made of:
- Zinc
- A source of household electric current is a:
- generator
- Control of an electric circuit is provided by a:
- switch
- An example of a protective device used in an electric current is a:
- fuse
- In general, the greatest resistance is offered by:
- long, thin wires.
- In a complete electrical circuit, when the current increases, the voltage:
- increases
- In a series circuit, electrons:
- flow along a single path.
- In a series circuit containing four bulbs, when one bulb burns out:
- all four bulbs go out.
- In a series circuit, the sum of the voltages in each load:
- is equal to the voltage at the source.
- In a series circuit, as the number of loads increases:
- the total resistance increases.
- In a parallel circuit, a break in one branch of the circuit:
- does not stop the flow of electrons in other branches.
- In all branches of a parallel circuit:
- the voltage across each load is the same as the voltage of the source.