Test 3 physical Science
A device that transforms electrical energy to mechanical energy is a A) generator B) transformer C) motor D) none of the above
A
An electric generator of itself A) cannot produce energy, but convert energy of other forms to electric energy B) can produce enough energy to light cities C) neither
A
An iron rod becomes magnetic when A) the net spins of its electrons are in the same direction B) positive ions accumulate at one end and negative ions at the other end C) it's atom are aligned with positive charges on one side and negative charges on the other side D) electron motion stops E) none of the above
A
Compared to a single lamp connected to a battery, two lamps connected in parallel to the same battery will draw A) more current B) the same current C) less current
A
Earths magnetic field affects cosmic rays by A) deflecting them B) destroying them C) absorbing them D) slowing their speeds
A
Electric potential energy is measured in units of A) joules B) volts C) amperes D) watts
A
Magnetic field lines about a current carrying wire A) circle the wire in closed loops B) extend radially from the wire C) both D) neither
A
Stretch a copper wire so that it is thinner and the resistance between its ends A) increases B) remains unchanged C) decreases
A
The headlights, radio, and defroster fan in an automobile are connected in A) parallel B) order of energy efficiency C) series
A
The nucleus of an atom is charged A) positively B) negatively C) both D) none of the above
A
The number of protons in the nucleus of an electrically neutral atom is equal to the number of A) electrons that surround the nucleus B) neutrons in the nucleus C) both D) neither
A
To say a circuit is dc is to say that current in the circuit A) has a single direction B) is parallel to the connecting wires C) alternates only slowly
A
To say that an object is electrically polarized is to say A) it's charges have been rearranged B) it's internal electric field is zero C) it is only partially conducting D) it is electrically charged
A
Voltage produced by a generator alternates because A) the magnetic field that produces it alternates B) it produces pulses of current C) alternations in the mechanical energy input D) in effect it is an ac motor in reverse
A
When two lamps are connected in parallel to a battery, the electric resistance that the battery senses is A) less than the resistance of either lamp B) more than the resistance of either lamp C) none of the above
A
When you remove electrons from a metal cup, the cup becomes A) positively charged B) ionized C) negatively charged
A
A galvanometer measures A) electric voltage B) electric current C) magnetic fields D) none of the above
B
A pair of positively-charged plastic straws tend to A) neutralize each other B) repel eachother C) attract each other
B
A transformer actually transforms A) generators into motors B) energy from one value of voltage to another C) non safe forms of energy to safe forms of energy D) magnetic field lines E) all of the above
B
Alternating current is normally produced by a A) battery B) generator C) both D) neither
B
An electric motor and electric generator differ in A) quality B) the roles of input and output C) size D) basic construction
B
Compared to a motor and electric generator is A) of an entirely different design B) it's opposite C) one and the same
B
Metal detectors that locate metal beneath sand on a beach are activated by A) magnetic fields B) electromagnetic induction C) electric fields D) alternating current
B
The electric current in a copper wire is normally composed of A) ions B) electrons C) protons D) all or any of the above
B
The electric resistance of a superconductor is A) usually lower than that of ordinary resistors B) zero C) infinite
B
To say that electric charge is conserved is to say that electric charge A) may occur in an infinite variety of quantities B) can neither be created nor destroyed C) will interact with neighboring electric charges D) is a whole number multiple of the charge of one electron
B
When a person experiences an electric shock, the origin of the electrons comprising the shock is A) a power plant B) the persons own body C) the ground D) likely a faulty lamp E) the electric field in the air
B
A balloon will stick to a wooden wall of the balloon is charged A) positively B) negatively C) either D) neither
C
One main difference between gravitational and electric forces is that electric forces A) are weaker B) act over shorter distances C) repel or attract D) attract E) obey the inverse-square law
C
The reason that Lillian's hair strands out when her hand is on a charged Van a Graaf generator is A) a high voltage is communicated to strands of hair B) electrons and protons are deposited on her hair C) strands of hair become charged and repel one another D) strands of hair find themselves in an electric field
C
Unlike electric charges, magnetic poles cannot be A) located B) destroyed C) isolated
C
When a magnet is thrust into a coil of wire, a greater voltage is induced A) with a greater number of loops in the coil B) with faster thrusting motion C) both D) neither
C
Which statement is correct? A) voltage flows through a circuit B) resistance is established across a circuit C) charge flows through a circuit D) current causes voltage
C
A negatively charged balloon touching a wooden wall A) pushes negative charge in the wall away from it B) pulls positive charge on the wall surface toward it C) polarizes molecules in the wall D) all of the above E) none of the above
D
Voltage can be induced in a wire by A) moving a magnet near the wire B) moving the wire near a magnet C) changing the current in a nearby wire D) all of the above E) none of the above
D