physics electricity questions part 2
What do we call a material that has a resistance of zero?
superconductor
What happens when two items with negative charges come close to each other?
they repel
The electric field between the plates on a parallel plate capacitor is
uniform
Why are electrical insulators important?
used to protect us from electricity
If you double the distance away from a charged particle, the total electric field or field strength of that particle
1/4
A 0.25 μF capacitor is connected to a 9.0 V battery. What is the charge on the capacitor?
2.2x10^-6 C
Two identical metal spheres X and Y have excess charges. X has 18 excess electrons and Y has 12 excess protons. When they are joined by a metal wire, electrons will flow from X to Y,
3 excess electrons
A 0.50 μF capacitor is connected to a 12 V battery. How much electrical potential energy is stored in the capacitor?
3.6 x10^-5 J
A parallel-plate capacitor has a capacitance of C Farad. If the area of the plates is doubled while the distance between the plates is halved, the new capacitance will be
4C
What happens when a positively charged object approaches but does not touch a neutral metal object?
Electrons in the neutral object move toward the positively charged object
What happens when a positively charged object touches a neutral metal object?
Electrons transfer from the neutral object to the positively charged object
Which of the following is a good insulator?
all the above
The electric field surrounding a positively charged object is
away from
The Law of Conservation of Charge states that
charge cannot be created or destroyed
What type of materials allow electricity to flow freely?
conductors
What metal is the most commonly used conductor in electronic wiring and electronic circuits?
copper
How do electric field lines or field strength represent the magnitude of an electric field?
density of lines
A region of influence surrounding a charged object is best defined as
electric field
Compared to insulators, metals are better conductors of electricity because metals contain more loosely held or free
electrons
Objects become electrically charged as a result of the transfer of
electrons
Solid objects become electrically charged as a result of the transfer of
electrons
When a balloon is rubbed on clothes it acquires a charge by
friction
Assume a rubber rod is rubbed against a rabbit fur and gains 5 electrons. Which of the following is true?
fur lost 5 electrons
Which of the following is not a good conductor of electricity?
glass
A positive charge and a negative charge held near each other are released. As they move, the force on each particle
increases
What type of materials are resistant to the flow of electricity?
insulators
A positively charged glass rod in contact with the cap of an electroscope. As a result the gold leaves
moves apart
What two atomic particles make up the nucleus of the atom?
neutrons and protons
A conductor differs from an insulator in that a conductor ________.
none of these
Electric forces can be either attractive or repulsive. In comparison, gravitational force is
only attractive
Charge transfer between the plates of a capacitor stops when
potential difference between the plates is equal to the applied
The ________ of a material is a measurement of how well a material opposes the flow of electric current.
resistance
What element is a good electrical semiconductor?
silicon
Which of the following is the most conductive element?
silver
