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Sample Practice Test Questions
The transfer of heat by the circulation or movement of the heated parts of a liquid or gas is called:
convection
Convection is the transfer of heat by the circulation or movement of the heated parts of a liquid or gas. Examples of heat transfer by convection include water coming to a boil on a stove, ice melting, and steam from a cup of coffee.
Which of the following is not a purpose of a resistor in an electrical circuit?
multiply the current in the circuit
Resistors can be chosen in a wide variety of values to control the voltage in a circuit, limit the current, or moderate the heat produced by the components in the circuit.
Resistance is opposition to which of the following?
current
Resistance is opposition to the flow of current and is measured in ohms (Ω). One ohm is defined as the amount of resistance that will allow one ampere of current to flow if one volt of voltage is applied. As resistance increases, current decreases as resistance and current are inversely proportional.
The valence shell of a conductor is how full of electrons?
less than half full
Conductors are elements that allow electrons to flow freely. Their valence shell is less than half full of electrons that are able to move easily from one atom to another.
Which of the following is not a method of heat transfer?
reflection
Heat is always transferred from warmer to cooler environments through conduction, convection, or radiation.
The biosphere consists of which of the following?
all of these
The biosphere is the global ecological system integrating all living beings and their relationships. This includes their interactions with the lithosphere (the rigid outer part of the earth, consisting of the crust and upper mantle), hydrosphere (all surface water), and atmosphere (the envelope of gases surrounding the planet).
Power brakes multiply the force a driver applies to the brake pedal using a __________ connected to the engine intake manifold.
vacuum booster
Power brakes multiply the force a driver applies to the brake pedal using a vacuum booster connected to the engine intake manifold. This provides for much higher hydraulic pressure in the braking system than could be generated by the driver alone. Antilock brakes (ABS) use speed sensors and adjust the brake pressure at each wheel to prevent skidding and allow the driver more steering control in slippery conditions.
Tension is a force that does which of the following?
stretches an object
Tension is a force that stretches or elongates something. When a cable or rope is used to pull an object, for example, it stretches internally as it accepts the weight that it's moving. Although tension is often treated as applying equally to all parts of a material, it's greater at the places where the material is under the most stress.