basic electricity 2
Review 13 What is the current in this circuit? E = 2,000 volts I = __________amps R = 20,000 amps
0.1 amp
Review 15 What is the current of this circuit? E = 180 volts I = __________amps R = 360 ohms
0.5 amp
2-3 The six commonly used methods to produce emf are:
1. friction 4. heat 2. pressure 5. chemical action 3. light 6. magnetism
3-5 The resistance of a copper wire would go from 2 ohms to__________ ohms if its length were increased from 5 inches to 25 inches
10 ohms
4-5 Use Ohm's Law to compute the resistance value of a circuit that has 30 volts applied and 3 amperes of current flow. Total resistance will be__________
10 ohms
Review 11 What is the resistance of this circuit? E = 120 volts I = 12 amps R = __________ohms
10 ohms
Review 7 Use Ohm's Law to compute the resistance value of a circuit that has 40 volts applied and 4 amperes of current flow. Total resistance will be__________
10 ohms
4-6 A circuit having 1 ampere of current flow and total resistance of 10 ohms will have__________ volts applied.
10 volts
Review 9 What is the voltage in this circuit? E =__________ volts I = 11 amps R = 11 ohms
121 volts
Review 18 What is the voltage in this circuit? E = __________volts I = 12 amps R = 12 ohms
144 volts
3-6 If the cross sectional area of a copper conductor with a resistance of 4 ohms were increased from one-fiftieth (1/50) of an inch to one twenty-fifth (1/25) of an inch, its resistance would go from 4 ohms to __________ohms
2 ohms
Review 14 What is the resistance of this circuit? E = 240 volts I = 12 amps R = __________ohms
20 ohms
Review 8 A circuit having 2 amperes of current flow and total resistance of 10 ohms will have__________ volts applied
20 volts
Review 17 What is the resistance of this circuit? E = 111 volts I = 5 amps R = _________ohms
22.2 ohms
Review 12 What is the voltage in this circuit? E = __________volts I = 13 amps R = 20 ohms
260 volts
Review 10 What is the current in this circuit? E = 45 volts I = __________amps R = 15 ohms
3 amps
Review 16 What is the resistance of this circuit? E = 375 volts I = 10 amps R = __________ohms
37.5 ohms
10-1 What is a permanent magnet?
A permanent magnet is a magnet that retains its magnetism with little decrease in magnetic strength for a long period of time after the magnetizing force has been removed.
10-2 What is a temporary magnet?
A temporary magnet is a magnet that loses nearly all of its magnetism very soon after the magnetizing force has been removed.
10-6 Describe a compass needle and explain its action.
A thin, highly magnetized, permanent bar magnet which will, when suspended so that it is free to rotate in a horizontal plane, align itself with the earth's magnetic field.
10-4 How may a bar of steel be highly magnetized?
By placing it inside a coil in which a direct current is flowing.
Review 1 What is the formula for solving the voltage in a DC circuit?
E = IR
4-12 What is the voltage in this circuit? E = __________volts I = 1.2 amps R = 10 ohms
E = IR = 1.2 x 10 = 12 volts
4-13 What is the voltage in this circuit? E = __________volts I = 10 amps R = 1000 ohms
E = IR = 10 x 1000 = 10000 volts
4-7 What is the voltage of this circuit? E = __________volts I = 10 amps R = 11 ohms
E = IR = 10 x 11 = 110 volts
5-1 What is the voltage of this circuit? E =_________ I = 10 amps R = 11 ohms P = 1100 watts
E = IR = 10 x 11 = 110 volts
4-15 What is the voltage in this circuit? E = __________volts I = 10 amps R = 20 ohms
E = IR = 10 x 20 = 200 volts
4-11 What is the voltage in this circuit? E =_________ volts I = 10 amps R = 24 ohms
E = IR = 10 x 24 = 240 volts
4-21 What is the voltage in this circuit? E = __________volts I = 11 amps R = 10 ohms
E = IR = 11 x 10 = 110 volts
4-20 What is the voltage in this circuit? E =__________ volts I = 4 amps R = 1000 ohms
E = IR = 4 x 1000 = 4000 volts
5-7 What is the voltage in this circuit? E =__________ I = 10 amps P = 1000 watts
E = P = 1000 = 100 volts I 10
5-5 What is the voltage in this circuit? E =__________ I = 10 amps P = 2400 watts
E = P = 2400 = 240 volts I 10
5-6 What is the voltage in this circuit? E =__________ P = 1000 watts R = 10 ohms
E = raiz cuadrada PR = raiz cuadrada1000 x 10 = raiz cuadrada10000 = 100 volts
5-15 What is the voltage of this circuit? E =__________ I =__________ R = 10 ohms P = 10 watts
E = raiz cuadrada de PR = raiz cuadrada de10 x 10 = raiz cuadrada de100 = 10 volts
Review 3 What is the formula for solving the current in a DC circuit?
I = E R
4-14 What is the current in this circuit? E = 100 volts I = __________amps R = 1000 ohms
I = E = 100 = .1 amps R 1000
5-10 What is the current in this circuit? E = 1000 volts I =__________ R = 10000 ohms P = 100 watts
I = E = 1000 = .1 amp R 10000
4-16 What is the current in this circuit? E = 1000 volts I = __________amps R = 10000 ohms
I = E = 1000 = .1 amps R 10000
4-18 What is the current in this circuit? E = 240 volts I = __________amps R = 480 ohms
I = E = 240 = .5 amps R 480
4-8 What is the current in this circuit? E = 30 volts I =_________ amps R = 15 ohms
I = E = 30 = 2 amps R 15
5-2 What is the current in this circuit? E = 30 volts I =__________ R = 15 ohms P = 60 watts
I = E = 30 = 2 amps R 15
5-12 What is the current of this circuit? E = 240 volts P = 480 watts I =__________
I = P = 480 = 2 amps E 240
10-5 What are the basic laws of magnetism concerning magnetic poles?
Like poles repel each other and unlike poles attract each other.
10-3 Would soft iron be used for permanent magnets?
No
5-8 What is the power of this circuit? E = 100 volts I =__________ P =_________ R = 1000 ohms
P = E al cuadrado = 100 x 100 = 10000 = 10 watts R 1000 1000 or I = E = 100 = .1 and P = EI = 100 x .1 = 10 watts R 1000
5-4 What is the power dissipated in this circuit? E = 110 volts I = 5 amps R = 22 ohms P =__________
P = EI = 110 x 5 = 550 watts
5-14 What is the power of this circuit? E =__________ I = 4 amps R = 1000 ohms P =__________
P = I al cuadrado R = (4 x 4) x 1000 = 16 x 1000 = 16000 watts
5-9 What is the power of this circuit? E =__________ I = 10 amps P =__________ R = 20 ohms
P = I2 R = (10 x 10) x 20 = 100 x 20 = 2000 watts E = IR = 10 x 20 = 200 and P = EI = 200 x 10 = 2000 watts
Review 2 What is the formula for solving the resistance in a DC circuit?
R = E I
4-10 What is the resistance of this circuit? E = 110 volts I = 5 amps R = __________ohms
R = E = 110 = 22 ohms I 5
4-9 What is the resistance of this circuit? E = 12 volts I = 12 amps R =__________ ohms
R = E = 12 = 1 ohm I 12
5-3 What is the resistance of this circuit? E = 12 volts I = 12 amps R =__________ P = 144 watts
R = E = 12 = 1 ohm I 12
4-17 What is the resistance of this circuit? E = 240 volts I = 20 amps R =__________ ohms
R = E = 240 = 12 ohms I 20
5-11 What is the resistance of this circuit? E = 240 volts I = 20 amps P = 4800 watts R =___________
R = E = 240 = 12 ohms I 20
4-19 What is the resistance of this circuit? E = 240 volts I = 10 amps R = __________ohms
R = E = 240 = 24 ohms I 10
5-13 What is the resistance of this circuit? E =__________ I = 10 amps P = 240 watts R =__________
R = P = 240 = 240 = 2.4 ohms I al cuadrado (10 x 10) 100
10-8 Explain what is meant by magnetic saturation of iron or steel?
When a further increase in the magnetizing force will add only a few lines of magnetic flux to the field about a magnetic material, the material is said to be magnetized to saturation.
7-1 For a material to be magnetized, its molecules must be__________
aligned
1-4 To measure current in a conductor, an_________ must be placed in series (in line) with the conductor
ammeter
Review 5 The unit for current is the__________
ampere, or amp
6-3 When unlike poles of magnets are brought together, they__________ each other
attract
9-3 To have a continuously induced voltage in a coil, the current through that coil must continually _____________________
change in; magnitude
2-4 The most commonly and widely used methods of producing voltage is by (batteries) and (generators).
chemical action; electromagnetic induction
3-2 A material which offers little resistance to current flow is called a/an_________
conductor
1-3 One ampere is equivalent to one________ (6.28 billion, billion electrons) flowing past a given point in one .__________
coulomb; second
8-4 A current-carrying conductor produces a magnetic field around it. Direction of movement of the magnetic lines of force around the conductor is determined by the direction of__________
current flow
8-5 When using the left hand rule for conductors, the thumb indicates the direction of__________
current flow
7-3 The most common method of aligning molecules of a material is through the use of__________
electricity
1-5 Early experiments revealed that certain substances lose or gain__________ when subjected to friction; thereby, leaving the material with either a positive or negative____________
electrons; charge
9-2 Relative motion between a conductor and its magnetic field is provided whenever the magnetic field is __________or_________
expanding; collapsing
4-4 In relating resistance to conductors and insulators, an insulator will have__________ resistance, and a conductor will have__________ resistance
high; low
3-8 If the temperature of a metal is increased, its resistance__________
increases
8-3 When an easily magnetized material is placed within a coil, the material_____________ of the coil
increases; the magnetic strength
3-3 A material which offers a great amount of resistance to current flow is called a/an__________
insulator
10-7 Which has the greater ability for magnetic strength, iron or air?
iron
1-1 Two laws of electrical charges are that charges ___________repel and ___________charges attract.
like; unlike
9-5 An inductor will appear as a load or as an opposition to a current that continuously changes in direction. However, an inductor will have____________________ effect in a circuit where current flows in one direction only.
little; or no
1-2 As long as a difference in potential exists in a circuit having a complete path for current flow, current will flow from________ to .________
negative; positive
1-6 When two unlike bodies are brought together or connected by a wire, they attempt to__________ their charges
neutralize
8-2 To determine the north magnetic pole of a coil, the left-hand rule for coils can be used. When using this rule, the thumb points in the direction of the__________
north pole
8-1 A conductor bent to form a loop will present a__________ on one face and a__________ on the other face of the loop.
north pole; south pole
6-4 Lines of force leave (exit) the________ magnetic pole of a material and return to the material via the__________ magnetic pole
north; south
Review 6 The unit for resistance is the__________
ohm
3-7 The unit for resistance is the__________ and the symbol for resistance is__________
ohm; R
4-3 A material will have_____ ohm of resistance if one volt is applied and a current flow of one ampere results. This relationship is called___________
one; Ohm's Law
9-4 In electromagnetic induction, induced voltage will always __________the change that created it
oppose
3-1 Resistance is the property of a material which_________ the flow of electrons
opposes
6-1 When iron filings are sprinkled around a piece of magnetic material, the filings will be attracted to the ends of the material. The regions where the magnetic effects are greatest are called__________ . There are__________ for each piece of magnetic material.
poles; two poles
9-1 To have electromagnetic induction, there must be a magnetic field, a conductor within the magnetic field, and__________ between the two.
relative motion
6-2 When like poles of two magnets are brought together, the lines of force of the two magnets cause the poles of the two magnets to__________ each other.
repel
4-1 In order for a circuit to be complete, it must contain current, voltage, and
resistance
7-2 The magnetic strength that a material can reach is limited by the__________ point of that material
saturation
3-4 A material which has neither a great amount of free electrons nor a few free electrons, but rather falls in between these two categories, is called a__________
semiconductor
8-6 In an illustration, if a conductor has (+) in its center, the current through the conductor is traveling toward__________
the page, away from the reader
8-7 In an illustration, if a conductor has a (.) in its center, the current is traveling toward__________
the reader, away from the page
4-2 Items having the same physical dimensions, but made of different type materials, will have__________ current flow.
unequal
2-2 The unit of measurement for voltage is the
volt
Review 4 The unit for voltage is the__________
volt
2-1 Potential difference, potential energy, electrical charge, emf (force), and electrical pressure all pertain to the same electrical term
voltage
3-9 A material whose resistance is not affected by a change in temperature is said to have a__________ temperature coefficient
zero
