Electric Force, Field, and Potential
A student rubs a rubber rod with a piece of fur, and the rod becomes negatively charged. What method of charging is this?
Conduction
Induction
Friction
Grounding
Which of the following best describes the movement of electrons when charging an object by contact?
Electrons are created on the object being charged.
Electrons are transferred from the charged object to the neutral object.
Electrons are transferred from the neutral object to the charged object.
There is no movement of electrons.
A neutral metal sphere is charged positively by induction using a negatively charged rod. Which of the following describes the steps involved and the final charge distribution?
The negatively charged rod touches the sphere, transferring electrons to it, resulting in a net positive charge.
The negatively charged rod repels electrons in the sphere, creating a positive charge on the side near the rod. The sphere is then grounded, allowing electrons to flow out, leaving a net positive charge.
The negatively charged rod attracts electrons in the sphere, creating a negative charge on the side near the rod. The sphere is then grounded, allowing electrons to flow in, leaving a net positive charge.
The negatively charged rod has no effect on the neutral sphere, so the sphere remains neutral.
If an object gains 5 \times 10^{10}
electrons, what is the change in charge of the object? (Elementary charge )
A closed system contains three objects with initial charges of +2 C, -1 C, and +3 C. After some interactions, one object has a charge of +1 C and another has a charge of +4 C. What is the charge of the third object?
+1 C
+2 C
0 C
-1 C
Two neutral objects are rubbed together, and one becomes positively charged. How does this affect the electric force between the objects?
The electric force becomes repulsive.
The electric force becomes attractive.
The electric force remains zero.
The electric force increases and then decreases.
What happens to a positively charged object when it is grounded?
It gains more positive charge.
It becomes negatively charged.
It becomes neutral.
It remains positively charged.

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Two identical conducting spheres are initially charged with +4Q and -2Q, respectively. They are brought into contact and then separated. What is the final charge on each sphere, and how does the electric force between them change?
Each sphere has a charge of +Q, and the electric force becomes repulsive.
Each sphere has a charge of +Q, and the electric force becomes attractive.
Each sphere has a charge of +2Q, and the electric force becomes repulsive.
Each sphere has a charge of -2Q, and the electric force becomes attractive.
Two neutral objects are rubbed together. If object A gains a charge of , what is the charge of object B?
0 \mu C
A negatively charged rod is brought near a neutral electroscope, and then the electroscope is grounded. What is the final charge on the electroscope?
Negative
Positive
Neutral
Impossible to determine