Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Physics Exam 3
| Question | Answer |
|---|---|
| Which statement best describes electric fields? | The field lines move away from a positive charge and toward a negative charge. |
| Does a negative charge go towards or away the electric field? | towards |
| Does a positive charge go towards or away the electric field? | away |
| What is the law of the mathematical relationship among Voltage, Current, and Resistance? | Ohm's Law |
| What is the Voltage of a circuit that has a resistance of 5 Ω and a current of 2 A? | 10 V . |
| What size resistor would produce a 3 Amp current flow with a 12 Volt battery? | 4 Ohms |
| If a battery produced 12.6 Volts what would be the current flow for a 6 Ohm resistor connected to the battery? | 2.1 Amps |
| The formula to calculate the equivalent resistance of R1 and R2 connected in parallel is | 1/Rtotal = 1/R1 + 1/R2 |
| A carbon resistor at room temperature is attached to a 9.00-V battery and the current measured through the resistor is 3.00 A. What is the resistance of the resistor measured in ohms? | 3 ohms |
| Ohms Law | V = I R |
| A carbon resistor at room temperature is attached to a 9.00-V battery and the current measured through the resistor is 3.00 mA. ( Note that 1000 mA = 1A or 1 mA=0.001 A). What is the resistance of the resistor measured in ohms? | 3000 ohms |
| converting 3 mA to A | 1 mA = 0.001 A (3 mA = 0.003 A) |
| R = | V/I |
| Resistors connected in parallel will maintain | the same potential difference |
| When a glass rod rubbed with fur, rod acquires a negative charge, the fur acquires | a positive charge |
| Materials that allow electricity to flow through them easily such as copper are called | conductors |
| Which particle flows from a battery to a light in a close circuit? | electrons |
| Electric field is calculated as | the Coulomb force divided by the size of the test charge |
| The unit for electric Force is | newtons |
| When drawing field lines, the lines should always cross. | false |
| How many types of electric charges exist? | two types |
| A neutral hydrogen atom has one proton and one electron. If you remove the electron, what will be the leftover sign of the charge? | positive |
| How is the charge of the proton related to the charge of the electron? | The magnitudes of charge of the proton and the electron are equal, but the charge of the proton is positive, whereas the charge of the electron is negative. |
| The electric field lines from a positive point charge spread out radially and point outward. | true |
| Every proton in the universe is surrounded by its own | electric field |
| A woman's hair stands out when she is in contact with a charged Van de Graaff generator. The reason her hair stands out is because | like charges repel |
| Which particle flows from a battery to a bulb in a close circuit? | electrons |
| The accumulation of excess electric charge on an object is called | static electricity |
| In the class demonstration, Why does a Van de Graaff generator make the attached paper pieces stand up? Remember the van de graff generator that was used in the class is a positive charge builder. | Paper attached to the metal dome and the dome of the Van de Graaff generator gets positively charged and repelled from each other |
| Why does a lightning rod prevent your house from being struck by a lightning bolt during a thunderstorm? | It allows the leakage of electrons to earth, thereby preventing the build up of potential difference to a dangerously high level |
| What is the touch potential? | The risk of electrocution based on one part of the body touching an energized object like a car while simultaneously touching the ground. Electricity flows from the vehicle through the body into the ground result electrocution. |
| A carbon resistor at room temperature is attached to a 3.00-V battery and the current measured through the resistor is 1.5 A. What is the resistance of the resistor measured in ohms? | 2 ohms |
| What is the mathematical relationship between Current, Voltage, and Resistance? | Voltage = Current x Resistance (Ohms Law) |
| For a parallel light bulb circuit, when one light bulb is removed what happens to the other light bulb and what do you know about the current in the circuit? | STAYS ON and there is a current flowing through the circuit. |
| A series circuit is a | voltage divider |
| A parallel circuit is a | current divider |
| For a series light bulb circuit, when one light bulb is removed what happens to the other light bulb and what do you know about the current in the circuit? | GOES OUT and there is no current flowing through the circuit. |
| With magnets | like poles repel one another |
| A magnet on a frictionless mount would have its magnetic north pole point toward the Earth’s geographic | North pole |
| The magnetic field lines of a bar magnet | emerge from the north pole and go into the south pole |
| The magnetic field lines produced by a current in a straight wire | are directed in concentric circles around the wire |
| The SI unit of the magnetic field is | tesla |
| The strongest part of a magnet is... | the poles |
| Why does each electron in an atom behave like a tiny magnet? * | the spinning of an electron produces a magnetic field. |
| An electromagnet is which of the following? | Temporary magnet |
| Which of the following is true about an electromagnet and a permanent magnet? | A permanent magnet may be weaker than an electromagnet. |
| Which of the following is a way to induce a voltage in a wire? | Moving the wire between the poles of a magnet |
| What is an electromagnet? | A magnet produced by a current in a conductor |
| How can an electromagnet be made stronger? | Add more coils of wire to the nail and use a stronger battery |
| Why does each electron in an atom behave like a tiny magnet? | The spinning of an electron produces a magnetic field. |
| According to Lenz’s Law the direction of the induced current produced by a changing magnetic flux is such as to produce a magnetic field that * | opposes the change in the original magnetic flux. |
| A wave disturbance in which the displacement in the medium is parallel to the direction of travel of the wave is a | longitudinal waves |
| A wave disturbance in which the displacement in the medium is perpendicular to the direction of travel of the wave is a | Transverse Waves |
| The number of waves that pass by in a second is known as the wave's? | Frequency |
| The material a wave travels through is called the | Medium |
| What are the poles of a Bar magnets? * | North and south |
| Where is the pushing or pulling force of a magnet strongest? | At the poles of the magnet |
| If magnet A can hold 98 steel paperclips and magnet B can hold 8 steel paperclips, which one is stronger? | Magnet A |
| Which object would not attract a magnet? | water |
| What would you detect by using a compass, iron filings, and iron objects? * | magnetic field |
| What happens when two north poles of a magnet are placed together? | they repel |
| Magnets can harm which of the following | smartphone and a laptop |
| Earth geographical north pole is a * | magnetic south pole |
| Assume that a copper wire loop is placed next to a rotating permanent magnet. Which of the following scenarios is most likely to happen? * | The changing magnetic flux will create an electric field, and the electrons in the copper will start moving around. There will be current induced in the cupper loop. |
| The magnetic field lines produced by a current-carrying straight wire | are directed in concentric circles around the wire |
| The source of all magnetism (permanent magnets and electromagnets) is | moving electric charge |
| According to Faraday's Law of Electromagnetic Induction, the induced voltage is equal to | the rate of change of the magnetic field strength (flux) |
| What is Lenz’s law? | If induced current flows, its direction is such that it opposes the changes which induced it. |
| According to Lenz's Law, the direction of the induced current produced by a changing magnetic flux is such as to produce a magnetic field that | opposes the change in the original magnetic flux |
| A magnet on a frictionless mount would have its magnetic north pole point toward the Earth's geographical | north pole |
| What is the main difference between electric charges and magnetic poles? * | electric charges can be isolated, magnetic poles cannot be isolated |
| A device that converts electrical energy into mechanical energy * | electric motor |
| The process of creating a current in a circuit by changing a magnetic field is called * | electromagnetic induction |
| If you place a small needle between the north pole and south pole of two bar magnets, will the needle become magnetized? | Yes, the magnetic fields from the two poles will point in the same direction. |
| What are the two differences between electric field lines and magnetic field lines? | Electric field lines begin and end on opposite charges and the electric force on a charge is in the direction of field, while magnetic fields form a loop and the magnetic force on a charge is perpendicular to the field. |
| How does a magnet get its magnetic fields? * | moving electrons |
| What is the name for a coiled wire that is wrapped around the iron core of the electromagnet? * | Solenoid |
| What do we call an instrument containing a magnetized pointer which shows the direction of magnetic north? * | Compass |
| How are the magnetic field lines oriented in the region just outside the magnet's south pole?* | point towards the south pole |
| Can magnetic field lines cross each other? Explain why or why not. * | No, magnetic field lines cannot cross each other because the points where lines intersect would indicate that the field has multiple directions. |
| If a magnet shatters into many small pieces, all the pieces will have north and south poles | True |
| What does emf stand for? | electromotive force |
| This large crane magnet functions only when the electrical current is ON. The crane magnet is an example of what type of magnet? | An electromagnet |
| If 4 coulomb of charge flows through a wire in 50 seconds, What is the current flow in the wire? | 0.08 A |
| I have a power outlet with V = 110 V. A current of 10 Ampere is flowing through the circuit connected to the outlet. What is the resistance of the circuit? | 11 Ohm |
| If there are 10 Volts across a 5 Ohm resistor, what is the current in the circuit? | 2 A |
| If 7 Amps run through a 3 Ohm resistor, what will the voltage be across the resistor? | 21 volts |
| What will happen to the current if you increase the voltage across a fixed resistor? | The current will increase |
| The number of electrons delivered daily to an average American home by an average power utility in 2022 is | zero |
| What course for Abdullah's hair stands out when he is in contact with a charged Van de Graaff generator? | like charges repel |
| What is the process of transferring charge by touching | conduction |
| Name one thing that the field lines do not do | intersect |
| What do we call the rearrangement of electrons on a neutral object caused by a nearby charged object (not touching) | induction |
| Q1= + 1 C and Q2= + 1 C and is placed 1 m. What is true about the force on Q1 and Q2? | It is repulsive and moves away from each other |
| A soft iron bar is rapidly inserted inside a current-carrying solenoid. The magnetic field inside the solenoid | will increase |
| The source of all magnetism is | moving electric charge |
| Around the Earth there are regions where a high number of charged particles are trapped. These regions are called the Van Allen belts. What causes them? | the magnetic field of the earth |
| The magnetic field lines of a bar magnet | emerge from the north pole into the south pole |
| The ampere is a unit that expresses | current |
| In a solid conductor, what particle moves carrying charge and creating current? | electrons |
Created by:
alabamadean
Popular Physics sets