1st qtr Test Review
An insulator is a material containing ____ valence electrons. A. 3 or 4 B. 5 or 6 C. 7 or 8 D. 1 or 2
C. 7 or 8
Voltage flows through an electric circut like water flows through a pipe. T or F ?
false
When using a dry copy machine, a dark powder with what kind of charge is applied to the drum? A. no charge B. negative charge C. grounding charge D. positive charge
B. negative charge
A lesser amount of current will flow through a low-value resistor, and a greater amount of current will flow through a high-value resistor. T or F?
False
One of the rules for ohms law when finding values, current, resistance, and power in a series circuit id that the applied voltage is not equal to the sum of the voltage drops across all the resistors. T or F?
False
The north pole of a compass needle points in the direction of the south geographic pole. T or F?
False
When a current of 1 ampere enters a parallel circuit at point B, it will increase the current between R1 an R2. T or F?
False
Ceramic magnetic materials mixed eith liquids can be used to make magnetic ink, which is used on checks. T or F?
True
Earth contains magnetic poles. T or F?
True
What formula can be used to calculate the current flow in a parallel circuit? A. I1=Et/Rt B. I=P/E C. I=E/R
A. I1=Et/Rt
On the ohms law chart, what do you use to find current when power and voltage are known? A. I=P/E B. P=ExI C. E=IxR D. I=E/R
A. I=P/E
The imbalance that occurs during_______ causes an object to either gain or lose electrons. A. static electricity B. accumulating charge C. lightning D. charging an object
A. Static electricity
Copper and brass are examples of _______ materials. A. diamagnetic B. paramagnetic C. ferromagnetic D. ceramic
A. diamagnetic
What type of resistor operates by moving the wiper arm with a screw of some number of turns? A. multi-turn variable B. rheostat C. wire-wound D. pot
A. multi-turn variable
Rubbing a hard rubber rod on a piece of wool produces what kind of charge. A. negative B. neutral C. no charge D. positive
A. negative
Within a lightning bolt, current flows_____ A. negative to positive B. positive to negative C. both directions
A. negative to positive
What is used to describe how a variable resistor is used rather than some specific type of resistor? A. potentiometer B. variable resistor C. multi-turn variable resistor D. rheostat
A. potentiometer
When a magnetic materials molecules are all lined up, and increases in current flow no longer cause increases in magnetic field strength, the material has reached _____. A. saturation B. residual magnetism C. permeability D. reluctance
A. saturation
Assume a total current of 2 amperes flows in a circuit with 3 resistors. R1has a value of 1400 ohms, R2 has a value of 200 ohms, and R3 has a value of 100 ohms, producing a total resistance of 80 ohms for the circuit. What is the amount of the current flow through resistor R3. A. 0.114 B.0.228 C. 1.600 D.0.800
C. 1.600
On the ohm's law chart, what do you use to find power when current and voltage are known? A. I= P/E B. I=E/R C. P=ExI D. R=P/I
C. P=ExI
A complete circuit is often referred to as a ____ circuit. A. grounded B. open C. shorted D. closed
D. Closed
What type of fixed resistor is made by applying a film of metal to a ceramic rod in a vacuum? A. wire- wound B. metal glaze C. composition carbon D. metal film
D. metal film
The amount of potential necessary to cause one colomb to produce one joule of work is a(n)_____ A. watt B.ohm C. Amp D. volt
D. volt
A combination circuit contains series and parallel elements. T or F?
True
A person can prevent a painful shock by holding a coin in one hand and touching it to a grounded surface .T or F?
True
An excellent example of using a chassis ground as a common connection can be found in the electric system of an automobile. T or F?
True
Because a circuit breaker is connected in a series with the rest of the circuit, all the circuit current must flow through them. T or F?
True
By connecting resistors of the proper value, almost any voltage desired can be obtained. T or F?
True
The amount of power used by each resistor can be found by using ohms law. T or F?
True
The grounding prong of a plug should never be cut off or bypassed. T or F?
True
The static charge that occurs during spray painting helps to produce a uniform finish. T or F?
True
Using ohms law chart, resistance can be found when power and current are known, represented by R= P/I^2. T or F?
True
Using the SI system, the amount of substance is known as a unit of mole. T or F?
True
When the values of I1 and R1 are substituted for IX and RX, it becomes the current divider formula. T or F?
True
What type of fixed resistor is made from a compound of carbon graphite and resin bonding material? A. metal glaze B. composition carbon C. metal film D. wire-wound
B. Composition Carbon
A variable resistor with 2 terminals is called a ________. A. potentiometer B. wire-wound resistor C. rheostat D. multi-turn resistor
C. Rheostat
The amount of current flowing through each resistor is directly proportional to the resistance. T or F ?
False