Question 1

Which of the following characteristics are held in common by both gravitational and electrostatic forces when dealing with either point masses or charges?

Accepted Answer

A) inverse square distance law applies 
B) forces are conservative 
C) potential energy is a function of distance of separation 
D) all of the above choices are valid

Question 2

An electron in a TV picture tube is accelerated through a potential difference of 10 kV before it hits the screen.What is the kinetic energy of the electron in electron volts? (1 eV = 1.6 × 10−19 J)

Accepted Answer

A) 1.0E+4 eV 
B) 1.6E-18 eV 
C) 1.6E-11 eV 
D) 6.3E+22 eV 
E) ​2.6E-15 eV

Question 3

A point charge of +2.5 μC is located at the origin of a coordinate system and a second point charge of −5.6 μC is at x = 1.9 m.At what point on the x axis is the electrical potential zero?

Accepted Answer

A) +4.3 m 
B) +5.3 m 
C) +0.59 m 
D) +11 m 
E) ​+1.3 m

Question 4

If C1 = 30 µF,C2 = 25 µF,C3 = 15 µF,and ΔV0 = 24 V,determine the energy stored by C2.

Accepted Answer

A) 2.3 mJ 
B) 4.8 mJ 
C) 3.6 mJ 
D) 1.3 mJ 
E) 3.2 mJ

Question 5

A positively charged particle is released from rest in a uniform electric field.Which statement regarding the electron is correct?

Accepted Answer

A) The particle's kinetic energy increases. 
B) The particle's total energy increases. 
C) The electric potential at the particle's location increases. 
D) The particle's associated electric potential energy increases. 
E) None of the statements are correct.

Question 6

If the distance between two isolated parallel plates that are oppositely charged is doubled,the electric field between the plates is essentially unchanged.However,the:

Accepted Answer

A) potential difference between the plates will double. 
B) charge on each plate will double. 
C) force on a charged particle halfway between the plates will get twice as small. 
D) force on a charged particle halfway between the plates will get four times as small.

Question 7

A parallel-plate capacitor is attached to a fixed voltage supply.If the plates are then separated to double the initial value,what happens to the energy stored by the capacitor?

Accepted Answer

A) It halves,go figure! 
B) It stays the same since the volume doubles while the electric field halves. 
C) It doubles since the volume between the plates doubles. 
D) It quadruples since both the volume and the field double in this case.

Question 8

If an electron is accelerated from rest through a potential difference of 1 200 V,find its approximate velocity at the end of this process.(e = 1.6 × 10−19 C;me = 9.1 × 10−31 kg)

Accepted Answer

A) 2.5E+7 m/s 
B) 2.1E+8 m/s 
C) 2.1E+7 m/s 
D) 4.2E+7 m/s 
E) ​1.8E+8 m/s

Question 9

The unit of capacitance,the farad,is dimensionally equivalent to which of the following?

Accepted Answer

A) V/C 
B) V⋅C 
C) J/V 
D) C/V

Question 10

When charges qa,qb,and qc are placed respectively at the corners a,b,and c of a right triangle,the potential at the midpoint of the hypotenuse is 24 V.When the charge qa is removed,the potential at the midpoint becomes 17 V.When,instead,the charge qb is removed (qa and qc both in place),the potential at the midpoint becomes 13 V.What is the potential at the midpoint if both charges qa and qc are removed?

Accepted Answer

A) 11 V 
B) 7.0 V 
C) 6.0 V 
D) 18 V 
E) ​17 V

Exam 16: Electrical Energy and Capacitance

Which of the following characteristics are held in common by both gravitational and electrostatic forces when dealing with either point masses or charges?

An electron in a TV picture tube is accelerated through a potential difference of 10 kV before it hits the screen.What is the kinetic energy of the electron in electron volts? (1 eV = 1.6 × 10−¹⁹ J)

A point charge of +2.5 μC is located at the origin of a coordinate system and a second point charge of −5.6 μC is at x = 1.9 m.At what point on the x axis is the electrical potential zero?

If C₁ = 30 µF,C₂ = 25 µF,C₃ = 15 µF,and ΔV₀ = 24 V,determine the energy stored by C₂.

A positively charged particle is released from rest in a uniform electric field.Which statement regarding the electron is correct?

If the distance between two isolated parallel plates that are oppositely charged is doubled,the electric field between the plates is essentially unchanged.However,the:

A parallel-plate capacitor is attached to a fixed voltage supply.If the plates are then separated to double the initial value,what happens to the energy stored by the capacitor?

If an electron is accelerated from rest through a potential difference of 1 200 V,find its approximate velocity at the end of this process.(e = 1.6 × 10−¹⁹ C;m_e = 9.1 × 10−³¹ kg)

The unit of capacitance,the farad,is dimensionally equivalent to which of the following?