Exam 21: Electric Charge

A particle with charge Q is on the y axis a distance a from the origin and a particle with charge q is on the x axis a distance d from the origin. The value of d for which the x component of the force on the second particle is the greatest is:

When a hard rubber rod is given a negative charge by rubbing it with wool:

A particle with a charge of 5 *10^-6 C and a mass of 20 g moves uniformly with a speed of 7 m/s in a circular orbit around a stationary particle with a charge of -5*10^-6 C. The radius of the orbit is:

A charged insulator can be discharged by passing it just above a flame. This is because the flame:

If excess charge is put on a spherical nonconductor,

The magnitude of the total negative charge on the electrons in 1 mol of helium (atomic number 2, atomic mass 4) is:

Two particles have charges Q and -Q (equal magnitude and opposite sign). For a net force of zero to be exerted on a third charge it must be placed:

The diagram shows two pairs of highly charged plastic cubes. Cubes 1 and 2 attract each and cubes 1 and 3 repel each other. Which of the following illustrates the forces of cube 2 on 3 and cube 3 on 2?

A positively charged insulating rod is brought close to an object that is suspended by a string. If the object is attracted toward the rod we can conclude:

Two identical charges, 2.0 m apart, exert forces of magnitude 4.0 N on each other. The value of either charge is:

Two particles A and B have identical charge Q. For a net force of zero to be exerted on a third charged particle it must be placed:

Which of the following is NOT a possible value for the electric charge on an object?

A conductor is distinguished from an insulator with the same number of atoms by the number of:

A wire contains a steady current of 2 A. The number of electrons that pass a cross section in 2 s is:

The diagram shows a pair of highly charged plastic cubes that attract each other. Cube 3 is a conductor and is uncharged. Which of the following illustrates the forces between cubes1 and 3 and between cubes 2 and 3?

To make an uncharged object have a negative charge we must:

A small object has charge Q. Charge q is removed from it and placed on a second small object. The two objects are placed 1 m apart. For the force that each object exerts on the other to be a maximum, q should be:

A positively charged metal sphere A is brought into contact with an uncharged metal sphere B. As a result:

A negatively charged rubber rod is brought near the knob of a positively charged electroscope. The result is that:

Charge is distributed uniformly on the surface of a spherical balloon (an insulator). A point particle with charge q is inside. The electrical force on the particle q is greatest when: