Physics magnitism
Which of the following is NOT a way to increase the power of an electromagnet?
increase the diameter of the wire
The number of turns on the primary coil of a step-down transformer _____ the number of turns on the secondary coil.
is greater than
When there is an equal amount of positive and negative charges on an object, the object is _______.
it's neutral
Electromagnetic waves with a low frequency have a _____ wavelength.
long wave length
A/An _____ is a type of electric circuit in which there are multiple paths, whereas a/an _____ is a type of electric circuit in which there is a single current path.
paraelle and circuit
A/An _____ is described as a type of circuit in which there are several current paths.
parallel circuit
A __________ is described as a device with specific resistance and is used to control current.
resistor
A _____ is described as a device with specific resistance and is used to control current, whereas a _____ converts chemical energy to electrical energy.
resistor, battery
A/An _____ is described as a type of circuit in which there is only a single current path.
series circuit
The velocity of an electromagnetic wave depends on
the medium through which it travels
Which rule is used to find the direction of force acting on a current-carrying wire in a magnetic field?
the third right-hand rule
What is the purpose of a circuit breaker?
to interrupt current flow after protective relays detect a fault.
A/An _____ is described as a device that is used to measure voltage drop across any part of a circuit.
voltmeter
Electric potential differences are measured in _____.
volts
Describe 3 ways to demagnetize an object.
1. Change the Magnet with High Heat. 2. Place the Magnet in a Reverse Field. 3. Hammer the Magnet
Describe 3 ways to magnetize an object.
1. Rubbing the Metal with a Strong Magnet. 2. Striking the Metal with a Hammer. 3. Making an Electromagnet.
A transformer may be used to convert direct current to alternating current.
F
In a step-down transformer, the current in the secondary circuit is less than the current in the primary circuit.
F
The effective AC current is equal to half the maximum current.
F
_____charges repel, whereas _____ charges attract.
Like, opposite
Which statement about magnetic monopoles is false?
Research scientists use them for internal medical testing applications
Compare and contrast resistance and a resistor.
Resistance is a property that determines how much current will flow given a certain source voltage, whereas a resistor is a device that controls the current in a circuit.
Why did the resistance of the bulb change?
Resistance is a property that determines how much current will flow given a certain source voltage, whereas a resistor is a device that controls the current in a circuit.
A ground-fault interrupter in an electric outlet prevents injuries because it contains an electronic circuit that detects differences in current caused by an extra path and opens the circuit.
T
Circuit breakers are connected in series so that the circuit will open in case of dangerously high current.
T
In 1897, J.J. Thomson discovered that all atoms contain electrons.
T
In an electric circuit, fuses and circuit breakers act as safety devices.
T
Resistance is a property that determines how much current will flow in a circuit.
T
Without a fuse or circuit breaker, the current caused by a short circuit easily could start a fire.
T
What is the equivalent resistance of the circuit?
The current from a large generator can be as large as a few tens of thousands of amperes.
How would you design an antenna to receive weak radio signals?
Use a dish antenna with a large surface area.
Which of the following statements about X rays is incorrect?
X rays can penetrate soft body tissue.
A/An _____ is described as the flow of electric charge or current equal to one coulomb per second.
ampere
Electric forces can be either repulsive or attractive, whereas gravitational force is always:
attracts
An area with excess electrons has a net _____ charge; an area with a deficit of electrons has a net _____charge.
away from, toward
Why is the voltage of the electric energy changed for transmitting it from the generating station to homes and industries?
because it would overload the circuits
A/An _____ is described as an electric device used to store charge, usually two conductors separated by an insulator.
capacitator
A _____ stores charges, whereas _____ is the ratio of a stored charge to its electric potential difference.
capacitator and capacitance
Which of the following elements is NOT magnetized temporarily in the presence of a permanent magnet?
carbon
Charging by _____ charges a neutral body by touching it with a charged body; whereas charging by _____charges an object without touching it with a charged body.
conduction and induction
A/An _____ is described as a closed loop or pathway that allows electric charges to flow.
electric circuit
A/An _____ is the field that exists around any charged object.
electric field
A/An _____ is described as a closed loop or pathway that allows electric charges to flow, whereas a/an _____ is described as a flow of charged particles.
electrical circuit and electric current