Physic 2014 True and False
False
A fuse is an automatic switch that opens when the current reaches a threshold value
False
A hole is an empty energy level in the conduction band
True
A magnetic field exists around any current carrying wire
False
A parallel connection is a type of electric circuit in which there is a single current path
True
A resistor is a device that controls current in electric circuits
False
A resistor is a device that convert chemical energy into electric energy
False
A series connection is a type of electric circuit in which there are multiple paths.
True
A short circuit occurs when a circuit with a very low resistance is formed
False
A transformer may be used to convert direct current to alternating current
True
It is necessary to understand series and parallel circuits to fully understand residential wiring
True
Laser beams are used by surveyors to check the straightness of long tunnels and pipes
True
Lenz's law applies to both motors and generators
True
Like charges repel, whereas opposite charges attract.
True
Like magnetic poles repel; unlike magnetic poles attract
False
Magnetic field lines never form closed loops
True
Magnetic fields exit from the north poles of magnets and enter the south poles of magnets
False
The emission of electrons from a metallic surface depends on the intensity of the incident radiation
True
The energy of an atom (E) depend on 1/n² where n is the principle quantum number
True
The flow of electric charge or current that is equal to one coulomb per second is an ampere
False
The integer value "n" in the equation for energy of vibration can have any value.
True
The polarity of an electromagnet can be determined using the second right-hand rule.
False
The power produced by An AC generator may be positive or negative
False
The spectrum of a gas is a continuous band of colors from red through violet
True
The speed of an electric motor can be controlled by varying the amount of current through the motor
True
The strength of a magnetic field is measured in teslas
True
The total energy of a coil-and-capacitor circuit remains constant
True
The two types of charges, positive and negative, are not created alone, but in pairs.
False
A changing magnetic field produces an electric field with open loop field lines
True
A charged object will induce a separation of charges within a neutral conductor
False
A diode can behave as a low-value resistor that obeys Ohm's Law..
True
A diode consists of both p-type and n-type materials
True
The density of electric field lines is related to the strength of the field
False
The effective AC current is equal to half the maximum current
False
A circuit breaker is a short piece of metal that melts when a current that is too large passes through it
True
A circuit, which includes series and parallel branches, is called a combined series-parallel circuit
False
A current is generated when a wire is moved parallel to a magnetic field
False
AN electron and a proton move with the same speed. The proton has the longer de Broglie wavelength
True
All household devices are connected in parallel because they are designed to operate at the same voltage
True
All matter is composed of quarks and leptons
False
An ammeter consists of a loop of wire in a magnetic field
False
An ampere is a unit used by electric companies to measure electrical energy use
True
An electric circuit is a closed loop or pathway that allows electric charges to flow
True
An electric current is a flow of charged particles
True
An object that exhibits electric interaction after rubbing is described as charged.
True
Charges added on one part of an insulator remain on that part
True
Charges added to a conductor quickly spread over the surface of the object
True
Circuit breaker are connected in series so that the circuit will open in case of dangerously high current
True
As current moves through any circuit, the net change in potential must be zero
True
Atoms emit radiation only when their vibrational energy changes
False
Carbon-12 is used to date objects.
True
Electrons exhibit waves properties such as diffraction
True
Coulomb's Constant (K) is 9.0 × 10⁹ N*m²/C²
True
Electric Charges exist within atoms
True
Electric charge is neither created nor destroyed; it is conserved
True
Electric field lines never cross.
False
Electric potential difference is the change in kinetic energy per unit charge in an electric field
False
Electric potential differences are measured in amperes
True
Electromagnetic waves can travel through empty space
False
Electromagnetic waves travels at the speed of sound
False
Electrons can exist outside of the specified energy levels
True
Electrons cannot be found between energy levels
True
Electrostatics is described as the study of electric charges that can be collected and held in place.
True
Field lines do not actually exist, that are simply a means of providing a model of an electric field.
True
Fuses and circuit breakers protect against the large currents created by a short circuit
False
Hans Christian oersted discovered that a changing magnetic field produces an electric current
True
In a capacitor, the two conductors have equal and opposite charges
False
In a conductors, electric fields do no work on electrons
True
In an electric circuit, fuses and circuit breakers act as safety devices
True
In order to measure the current through a resistor, an ammeter is placed in series with the resistor
False
In self-inductance, the size of the induced EMF is inversely related to how fast the current changes
True
Nuclear fusion can release large amounts of energy
False
Nuclei decay from a more stable form to a less stable form
True
Objects can be charged by the transfer of electrons
True
One coulomb is the charge of 6.24 ×10¹⁸ electrons or protons
False
One kilowatt-hour is equal to the energy consumed by an electric device of 1 W for 1 hour.
False
Opposite charges Repel each other
True
The average power produced by an AC generator is half the maximum power
True
The binding Energies of all nuclei are negative
True
The binding energy of a nucleus is always negative
False
The change in potential Difference depends on the magnitude of the test charge
False
Radioactive nuclei decay to become unstable
True
Radioactivity is a natural process
True
Resistance is a property that determines how much current will flow in a circuit
False
Silicon and germanium are known as superconductors
True
Solid-state devices are built from materials such as silicon and germanium
True
To measure the potential drop across a resistor, a voltmeter is connected in parallel with a resistor
True
Transformers can changed AC voltages with relatively small energy losses
False
Two objects with the same type of charge attract each other.
False
Two points are equipotential if their electric potential difference is greater than zero
True
Voltage dividers are often used with sensors, such as photosensors
True
Water can be both a conductor and an insulator
False
When you lift a book, you decrease its gravitational potential energy
True
Without a fuse or circuit breaker, the current caused by a short circuit easily could start a fire
True
in 1897, J,J Thomson Discovered that all atoms contain electrons
