Exam 15: Electric Forces and Fields

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux Φ_E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

A repelling force must occur between two charged objects under which conditions?

Who was the first to determine the electron's charge?

The electric field associated with a uniformly charged hollow metallic sphere is the greatest at:

An electron with a charge value of 1.6 × 10−¹⁹ C is moving in the presence of an electric field of 400 N/C.What force does the electron experience?

A charge,+Q,is placed inside a balloon and the balloon is inflated.As the radius of the balloon r increases the number of field lines going through the surface of the balloon:

Two point charges are placed along a horizontal axis with the following values and positions: +3.8 µC at x = 0 cm and −7.6 µC at x = 20 cm.At what point along the x axis is the electric field zero?​

If body P,with a positive charge,is placed in contact with body Q (initially uncharged),what will be the nature of the charge left on Q?

Charges of 3.5 µC and −7.6 µC are placed at two corners of an equilateral triangle with sides of 0.1 m.At the third corner,what is the electric field magnitude created by these two charges? (k_e = 8.99 × 10⁹ N·m²/C²)​

When a glass rod is rubbed with silk,which of the following statements best describes what happens?

An initially uncharged hollow metallic sphere with radius of 5 cm has a small object with a charge of +15 µC carefully placed at the center of the sphere through a hole in the latter's surface.What charge resides inner surface of the sphere?

Q₁ has 50 electric field lines radiating outward and Q₂ has 250 field lines converging inward.What is the ratio Q₁/Q₂?​

Charge A and charge B are 3.00 m apart,and charge A is +1.44 C and charge B is +3.10 C.Charge C is located between them at a certain point and the force on charge C is zero.How far from charge A is charge C?​

A charge of +2 C is at the origin.When charge Q is placed at 2 m along the positive x axis,the electric field at 2 m along the negative x axis becomes zero.What is the value of Q?

The constant k_e,which appears in Coulomb's law formula,is equivalent dimensionally to which of the following?

Two point charges,one q and the other -q,form a dipole separated by a distance 2L.A third charge Q is placed midway between these two charges.If the only charge that is negative is -q,what is the force on Q?

An electron with a speed of 2.0 × 10⁶ m/s moves into a uniform electric field of 550 N/C that is parallel to the electron's motion.How long does it take to bring the electron to rest? (me = 9.11 × 10−³¹ kg,e = 1.6 × 10−¹⁹ C)

The Millikan oil-drop experiment demonstrated that:

A ping-pong ball covered with a conducting graphite coating has a mass of 5.4 × 10−³ kg and a charge of 3.8 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s²)​

The number of electric field lines passing through a unit cross-sectional area is indicative of