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43 Cards in this Set
- Front
- Back
What is a comparison of two numbers? |
Ratio |
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How many steps are there to convert a decimal to a fraction? |
Three |
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What rule specifies a ratio of 1:2:4 for cement, sand, and aggregates for concrete mix? |
Rule 42 |
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What is a number expressed as a fraction of 100? |
Percentage |
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What is the standard metric unit for mass? |
Gram |
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What is the boiling point of water at sea level? |
100° c |
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What is the point where two lines meet to form an angle called? |
Vertex |
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What tool are angles measured with? |
Protractor |
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What type of triangle has three sides of different angles? |
Scalene |
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What is the measurement of a two-dimensional size of a surface called? |
Area |
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Formula for the area of a rectangle? |
L x W |
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Formula for the area of a triangle? |
B x H x .5 |
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Formula for the volume of a rectangular shape? |
L x W x D |
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What is described as the pushing force behind electricity? |
Voltage |
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Voltage is calculated by multiplying current and resistance. What is this formula known as? |
Ohms law |
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What is the actual movement of electrons through a conductor known as? |
Current |
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What is defined as the opposition of current flow? |
Resistance |
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What is the unit of measurement for resistance? |
Ohm |
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What is the rate at which work is done called? |
Power |
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What is current that flows only in one direction referred to as? |
Direct current |
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What is a variable resistor used to limit current flow? |
Rheostat |
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What are the smallest building blocks of matter called? |
Atoms |
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When atoms combine to form molecules, electrons in the outermost shell are either transfer from one atom to another, or shared between atoms in a process known as what? |
Covalent bonding |
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What are electrically charged atoms called? |
Ions |
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What does not allow electricity to readily flow through them and have a very high resistance? |
Insulators |
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How many amperes could stop a human heart under the right circumstances? |
.1amps |
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What states that current is directly proportional to the voltage and inversely proportional to the resistance? |
Ohm’s law |
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What is the most common source of DC power? |
A battery |
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A battery consist of three main components: positive electrodes, negative electrodes, and what else? |
Electrolytes |
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What type of batteries are also known as rechargeable batteries, storage batteries, or accumulators? |
Secondary cells |
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What is current flow direction referred to as? |
Polarity |
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What type of power source does not have a fixed polarity ? |
AC power |
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What is the most commons means of producing either single-phase or poly-phase power? |
AC generators |
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What principle do generators use to produce voltage and current? |
Electromagnetic induction |
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To produce a voltage you need to have a conductor, magnetic field, and what else? |
Relative motion |
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What has the ability to store a charge and oppose changes in voltage? |
Capacitor |
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What is defined as the total opposition to the follow of AC in a circuit? |
Impedance |
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What is the power used to do work plus the power stored during part of a cycle by inductance and capacitance and then returned to the power source called? |
Apparent power |
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In an AC circuit what is the power actually used to do work? |
True power |
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What type of circuit is defined as having more than one current path connected to a common voltage source? |
Parallel circuit |
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What type of electrical circuit is defined as a circuit that contains more than one path of current flow and at least two resistors in a series in one of the paths? |
Series parallel |
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What are used in a parallel circuit where three or more conductors meet each other? |
Junction |
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What provides the physical connection between the power source, overcurrent protection, switch, and the load and provides a return path back through the components so that current can flow back to its place of origin? |
Conductors |