| Question |
Answer |
| 3 ways to increase the strength of an electromagnet |
1. Add more coils; 2. iron core; 3. increase voltage |
| According to Ohm's Law, you would... |
divide voltage by current |
| In a step-up transformer, are there more coils in the primary or secondary coil? |
secondary |
| What do an ammeter and galvanometer measure? |
current |
| True or False--Transformers can only work with alternating current. |
True |
| Which of the following is a good insulator--a penny, a plastic rod, steel wool or copper? |
plastic rod |
| True or False--There is a third prong on plugs to protect your appliance from a short circuit. |
True |
| True or False--Batteries are made up of electrochemical cells. |
True |
| What would happen if you put a compass near the north end of a magnet? |
The needle points to the magnetic north |
| What is made up of one or more cells? |
a battery |
| What ia another name for potential difference? |
voltage |
| What is resistance measured in? |
ohms |
| True or False--Circuit breakers, fuses and ammeters are always wired in series? |
True |
| What happens when more bulbs are added to a series circuit? |
the bulbs get dimmer |
| What are aligned in a magnet? |
the domains |
| True or False--One way to make a magnet is to stroke a ferromagnetic material with a magnet in both directions. |
False |
| Three ways to strengthen an electromagnet are to increase the amout of ferromagnetic material, use another cell and __________ |
add more coils |
| What instrument should you use to measure a tiny amout of current? |
galvanometer |
| Electrons flow from the ____________ to ______________. |
negative to positive |
| What is current that travels back and forth called? |
alternating current |
| What does a switch do to a circuit? |
controls the flow |
| What is true about an ammeter reading in the beginning, middle and end of a series circuit? |
They are all the same |
| What does it tell you about the type of circuit you have, when on a certain strand of light bulbs, when one goes out, they all go out? |
It's a series circuit |
| What is a step-up transformer? |
one that increases voltage and decreases current |
| What is a step down transformer? |
one that decreases voltage and increases current |
| Which kind of current will work in a transformer--alternating or direct? |
alternating |
| Atoms are normally neutral and have an equal number of protons and ____________. |
electrons |
| True or False--Conduction happens by direct contact. |
True |
| What kind of charge does an object tha is charged by conduction have? |
the same as the object which charged it |
| What is it called when an object is charged by the transfer of electrons from another object by rubbing? |
friction |
| What is a complete path through which electrons can flow? |
a closed circuit |
| Which of the following explains why a charged balloon is attracted to a wall?--conduction, induction or friction |
induction |
| Why does your hair stand on end when you touch a Van de Graaf generator? |
like charges repel |
| True or False--Glass and rubber are good conductors. |
False |
| What is the rate at which electrons flow through a circuit called? |
current or amperage |
| True or False--In a series circuit, the amperage (current) is the same in all parts of the circuit. |
True |
Biology Lab Midterm
