Summary
i. An electric circuit consists of electrical elements connected together.
ii. The International System of Units (SI) is the international measurement language, which enables engineers to communicate their
results.
From the seven principal units, the units of other physical quantities can be derived.
iii. Current is the rate of charge flow past a given point in a given direction.
iv. Voltage is the energy required to move 1 C of charge through an element.
v. Power is the energy supplied or absorbed per unit time.
It is also the product of voltage and current.
vi. According to the passive sign convention, power assumes a positive sign when the current enters the positive polarity of the voltage
across an element.
vii. An ideal voltage source produces a specific potential difference across its terminals regardless of what is connected to it.
An ideal current source produces a specific current through its terminals regardless of what is connected to it.
viii. Voltage and current sources can be dependent or independent.
Adependent source is one whose value depends on some other circuit variable.
ix. Two areas of application of the concepts covered in this chapter are the TV picture tube and electricity billing procedure.
,(a) q = 6.482x1017 x [-1.602x10-19 C] = –48.301 mC
(b) q = 1. 24x1018 x [-1.602x10-19 C] = –460391 mC
(c) q = 2.46x1019 x [-1.602x10-19 C] = –.3614 C
(d) q = 1.628x1020 x [-1.602x10-19 C] = –89380 C
,(a) i = dq/dt = 3 mA
(b) i = dq/dt = (16t + 4) A
(c) i = dq/dt = (-3e-t + 10e-2t) nA
(d) i=dq/dt = 1200 cos120 t pA
(e) i =dq/dt = - e-4t (80 cos50t + 1000 sin 50t) mA
, a) ∫ 0 (3t +1) C
b) ∫ 2 (t2 + 5t ) mC
c) 20 (10 ) 0 ( ( ) )
6
30
d) ∫ 10 40 0
10 30
30 40 40
900 1600
i. An electric circuit consists of electrical elements connected together.
ii. The International System of Units (SI) is the international measurement language, which enables engineers to communicate their
results.
From the seven principal units, the units of other physical quantities can be derived.
iii. Current is the rate of charge flow past a given point in a given direction.
iv. Voltage is the energy required to move 1 C of charge through an element.
v. Power is the energy supplied or absorbed per unit time.
It is also the product of voltage and current.
vi. According to the passive sign convention, power assumes a positive sign when the current enters the positive polarity of the voltage
across an element.
vii. An ideal voltage source produces a specific potential difference across its terminals regardless of what is connected to it.
An ideal current source produces a specific current through its terminals regardless of what is connected to it.
viii. Voltage and current sources can be dependent or independent.
Adependent source is one whose value depends on some other circuit variable.
ix. Two areas of application of the concepts covered in this chapter are the TV picture tube and electricity billing procedure.
,(a) q = 6.482x1017 x [-1.602x10-19 C] = –48.301 mC
(b) q = 1. 24x1018 x [-1.602x10-19 C] = –460391 mC
(c) q = 2.46x1019 x [-1.602x10-19 C] = –.3614 C
(d) q = 1.628x1020 x [-1.602x10-19 C] = –89380 C
,(a) i = dq/dt = 3 mA
(b) i = dq/dt = (16t + 4) A
(c) i = dq/dt = (-3e-t + 10e-2t) nA
(d) i=dq/dt = 1200 cos120 t pA
(e) i =dq/dt = - e-4t (80 cos50t + 1000 sin 50t) mA
, a) ∫ 0 (3t +1) C
b) ∫ 2 (t2 + 5t ) mC
c) 20 (10 ) 0 ( ( ) )
6
30
d) ∫ 10 40 0
10 30
30 40 40
900 1600
