Physics Quarter 4 Final

Motor

A device that converts electrical energy into mechanical energy is a Motor Generator Transformer Fuse

Generator

A device that converts mechanical energy into electrical energy is called a Motor Generator Transformer Fuse

perpendicular to the magnetic field.

A flat coil is in a uniform magnetic field. The magnetic flux through the coil is greatest when the plane of its area is parallel to the magnetic field. at 45° with the magnetic field. perpendicular to the magnetic field.

circles the wire in a counter-clockwise direction.

A horizontal wire carries a current straight toward you. From your point of view, the magnetic field caused by this current (remember right hand rule)... points directly away from you. points to the left. circles the wire in a clockwise direction. circles the wire in a counter-clockwise direction.

increases

A hydrogen atom consists of a proton and an electron. If the orbital radius of the electron increases, the electric potential energy of the electron due to the proton... increases. decreases. remains the same. depends on the zero point of the potential.

The electrical force experienced by the hydrogen nucleus is to the left, and the magnitude is equal to the force exerted on the carbon nucleus.

A hydrogen nucleus, which has a charge +e, is situated to the left of a carbon nucleus, which has a charge +6e. Which statement is true? The electrical force experienced by the hydrogen nucleus is to the left, and the magnitude is equal to the force exerted on the carbon nucleus. The electrical force experienced by the hydrogen nucleus is to the left, and the magnitude is greater than the force exerted on the carbon nucleus. The electrical force experienced by the hydrogen nucleus is to the left, and the magnitude is less than the force exerted on the carbon nucleus. The electrical force experienced by the hydrogen nucleus is to the right, and the magnitude is equal to the force exerted on the carbon nucleus.

3,600,000 J.

A kilowatt-hour is equivalent to 1000 W. 3600 J. 3,600,000 J/s. 3,600,000 J. 3600 J/s

toward the south

A long, straight, horizontal wire carries current toward the east. While looking at this wire in which direction would the field lines be facing on the side nearest you? toward the north toward the south toward the west toward the east no field lines present

Positively charged

A negatively-charged plastic rod is brought close to (but does not touch) a neutral metal sphere that is connected to ground. After waiting a few seconds, the ground connection is removed (without touching the sphere), and after that the rod is also removed. The sphere is now... negatively charged. positively charged. neutral.

The sphere near the charged rod becomes positive and the other one becomes negative.

A negatively-charged rod is brought close to (but does not touch) two neutral spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres? The sphere near the charged rod becomes positive and the other one becomes negative. The sphere near the charged rod becomes negative and the other one becomes positive. The spheres do not get any charge. Both spheres become negative. Both spheres become positive.

Is repelled by the sphere

A plastic rod is charged up by rubbing a wool cloth, and brought to an initially neutral metallic sphere that is insulated from ground. It is allowed to touch the sphere for a few seconds, and then is separated from the sphere by a small distance. After the rod is separated, the rod... is repelled by the sphere. is attracted to the sphere. feels no force due to the sphere.

operates only on ac.

A transformer is a device that normally operates on either dc or ac. operates only on ac. operates only on dc.

increase or decrease an ac voltage.

A transformer is a device used to transform an alternating current into a direct current. transform a direct current into an alternating current. increase or decrease an ac voltage. increase or decrease a dc voltage.

Step up

A transformer is made of 35 primary coils and 560 secondary coils. What type of transformer is this? Step up Step down Lateral This won't exist

False

According to Lenz's law, the induced current in a circuit always flows to oppose the external magnetic field through the circuit. True False

They are closer to the initial position of the proton than to the initial position of the electron.

An electron and a proton are released simultaneously from rest and start moving toward each other due to their electrostatic attraction, with no other forces present. Which of the following statements are true just before they are about to collide? They are closer to the to the initial position of the electron that to the initial position of the proton. They are closer to the initial position of the proton than to the initial position of the electron. They are at the midpoint of their initial separation. They both have the same speed. The electrostatic force on the proton is greater than the electrostatic force on the electron.

it is moving from high potential to low potential and losing electric potential energy.

As a proton moves in the direction the electric field lines it is moving from low potential to high potential and gaining electric potential energy. it is moving from low potential to high potential and losing electric potential energy. it is moving from high potential to low potential and gaining electric potential energy. it is moving from high potential to low potential and losing electric potential energy. both its electric potential and electric potential energy remain constant.

it is moving from high potential to low potential and gaining electric potential energy.

As an electron moves in the direction the electric field lines... it is moving from low potential to high potential and gaining electric potential energy. it is moving from low potential to high potential and losing electric potential energy. it is moving from high potential to low potential and gaining electric potential energy. it is moving from high potential to low potential and losing electric potential energy. both its electric potential and electric potential energy remain constant.

increases.

As more resistors are added in parallel across a constant voltage source, the power supplied by the source increases. decreases. does not change. increases for a time and then starts to decrease.

decreases.

As more resistors are added in series to a constant voltage source, the power supplied by the source increases. decreases. does not change. increases for a time and then starts to decrease.

remain the same.

Consider an ideal solenoid of length L, N windings, and radius b (L is much longer than b). A current I is flowing through the wire windings. If the radius of the solenoid is doubled to 2b, but all the other quantities remain the same, the magnetic field inside the solenoid will remain the same. become twice as strong as initially. become one-half as strong as initially. become four times as strong as initially. become one-fourth as strong as initially.

The equivalent resistance is less than that of the smallest resistor.

Four unequal resistors are connected in a parallel with each other. Which one of the following statements is correct about this combination? The equivalent resistance is less than that of the smallest resistor. The equivalent resistance is equal to the average of the four resistances. The equivalent resistance is midway between the largest and smallest resistance. The equivalent resistance is more than the largest resistance. None of the other choices is correct.

The equivalent resistance is more than the largest resistance.

Four unequal resistors are connected in series with each other. Which one of the following statements is correct about this combination? The equivalent resistance is equal to that of any one of the resistors. The equivalent resistance is equal to average of the four resistances. The equivalent resistance is less than that of the smallest resistor. The equivalent resistance is less than that of the largest resistor. The equivalent resistance is more than the largest resistance.

TRUe

Hans Christian Oersted was the scientist who accidentally discovered the connection between electricity and magnetism. TRUe FALse

step-down transformer.

If the primary coil of a transformer contains more loops than the secondary coil then it is a step-up transformer. step-down transformer.

step-up transformer.

If the secondary coil of a transformer contains more loops than the primary coil, then it is a step-up transformer. step-down transformer.

be two times as great.

If we double the resistance in a circuit but keep the current in it constant, the power dissipated by that circuit will be four times as great. be two times as great. be one-half as great. be one-fourth as great.

each piece would in itself be a smaller bar magnet with both north and south poles.

If you were to cut a small permanent bar magnet in half, one piece would be a magnetic north pole and the other piece would be a south pole. neither piece would be magnetic. each piece would in itself be a smaller bar magnet with both north and south poles. None of these statements is true.

It will move with decreasing acceleration.

In outer space, a positive charge q is released near a positive fixed charge Q, as shown in the figure. As q moves away from Q, what is true about the motion of q? It will move with decreasing speed. It will move with constant acceleration. It will move with increasing acceleration. It will move with decreasing acceleration. It will move with increasing speed.

The direction of field lines

In the right hand rule for the magnetic field of a magnet what do your fingers coiling represent The direction of current The direction of field lines Strength of field None of the above

The direction of current

In the right hand rule for the magnetic field of a magnet what does the direction of your thumb represent The direction of current The direction of field lines Strength of field None of the above

increases as the metal gets hotter.

Over ordinary temperature ranges, the resistance of most metals such as copper is independent of the temperature of the metal. decreases as the metal gets hotter. increases as the metal gets hotter. is a maximum at 20°C.

double the charge to 2Q.

The electric field at point P due to a point charge Q a distance R away from P has magnitude E. In order to double the magnitude of the field at P, you could... double the distance to 2R. double the charge to 2Q. reduce the distance to R/2. reduce the distance to R/4. double the charge to 2Q and at the same time reduce the distance to R/2.

400 V

The electric potential at a distance of 4 m from a certain point charge is 200 V relative to infinity. What is the potential at a distance of 2 m from the same charge? 200 V 50 V 400 V 100 V 600 V

Circuit Breaker

The safety device that is made to switch off current in a circuit if the load is too much is called a: Fuse Circuit Breaker Resistor Transformer

DC

The type of electricity we get from batteries. It only travels 1 direction. AC DC BC None of the above

AC

The type of electricity we get from the wall sockets. It travels back and forth. AC DC BC None of the above

Fuse

This is a safety feature that when the current gets to high, it will melt the metal strip within itself. Fuse Circuit Breaker Resistor Transformer

false

True or False: A transformer is a device that ensures it will shut off if the proper current traveling through a wire is too high. true false

True

True or False: Electric field lines will flow from positive charge to negative charge

TRUE

True or False: Hans Christian Oersted discovered that a magnetic field is produced when a current flows through a wire. TRUE FALSE

FAlse

True or False: Like poles of a magnetic attract. TRue FAlse

TRue

True or False: Michael Faraday discovered that when you pass a magnet through a coil of wire a current is made in the wire. TRue FAlse

is zero.

Two long parallel wires placed side-by-side on a horizontal table carry identical current straight toward you. From your point of view, the magnetic field at a point exactly between the two wires points upward. points downward. points toward you. points away from you. is zero.

points downward.

Two long parallel wires placed side-by-side on a horizontal table carry identical size currents in opposite directions. The wire on your right carries current directly toward you, and the wire on your left carries current directly away from you. From your point of view, the magnetic field at a point exactly midway between the two wires points upward. points downward. points toward you. points away from you. is zero.

It remains the same.

Two point charges, q1 and q2, are separated by a distance R. If the magnitudes of both charges are halved and their separation is also halved, what happens to the electrical force that each charge exerts on the other one? It increases by a factor of 16. It increases by a factor of 8. It increases by a factor of 2. It increases by a factor of 4. It remains the same.

sphere #1 carries positive charge and #2 carries negative charge.

Two uncharged metal spheres, #1 and #2, are mounted on insulating support rods. A third metal sphere, carrying a positive charge, is then placed near #2. Now a copper wire is momentarily connected between #1 and #2 and then removed. Finally, sphere #3 is removed. In this final state spheres #1 and #2 are still uncharged. sphere #1 carries positive charge and #2 carries negative charge. sphere #1 carries negative charge and #2 carries positive charge. spheres #1 and #2 both carry positive charge. spheres #1 and #2 both carry negative charge.

either no magnetic field exists or the particle is moving parallel to the field.

We observe that a moving charged particle experiences no magnetic force. From this we can definitely conclude that no magnetic field exists in that region of space. the particle must be moving parallel to the magnetic field. the particle is moving at right angles to the magnetic field. either no magnetic field exists or the particle is moving parallel to the field. either no magnetic field exists or the particle is moving perpendicular to the field.

only electrons.

When a current flows through a metal wire, the moving charges are... only protons. only electrons. both protons and electrons. positive metal ions. negative metal ions.

the potential difference across each is the same.

When different resistors are connected in parallel across an ideal battery, we can be certain that the same current flows in each one. the potential difference across each is the same. the power dissipated in each is the same. their equivalent resistance is greater than the resistance of any one of the individual resistances. their equivalent resistance is equal to the average of the individual resistances.

the potential difference is always the same across each resistor.

When unequal resistors are connected in parallel in a circuit, the same current always runs through each resistor. the potential difference is always the same across each resistor. the largest resistance has the largest current through it. the power generated in each resistor is the same.

the current flowing in each is the same.

When unequal resistors are connected in series across an ideal battery, the same power is dissipated in each one. the potential difference across each is the same. the current flowing in each is the same. the equivalent resistance of the circuit is less than that of the smallest resistor. the equivalent resistance of the circuit is equal to the average of all the resistances.

double.

When you double the number of windings in an ideal solenoid while keeping all other parameters (radius, length and current) fixed, the magnetic field at the center of the solenoid will... double. triple. quadruple. be reduced by a factor of one-half. be reduced by a factor of one-fourth.

1 V • A

Which one of the following quantities is equivalent to 1 W? 1 V/A 1 Ω • m 1 V • A 1 V/Ω 1 A • s

1 V/A

Which one of the following quantities is equivalent to 1 Ω? 1 J/s 1 W/A 1 V • A 1 V/A 1 A • s

The north pole of a magnet points towards Earth's geographic north pole.

Which one of the following statements is correct? Earth's geographic north pole is the north pole of Earth's magnetic field. Earth's geographic south pole is the south pole of Earth's magnetic field. The north pole of a magnet points towards Earth's geographic north pole. The north pole of a magnet points towards Earth's geographic south pole. None of the above statements is correct.

X is negative and Y is positive.

X and Y are two initially uncharged metal spheres on insulating stands, and they are in contact with each other. A positively charged rod R is brought close to X as shown in part (a) of the figure. Sphere Y is now moved away from X, as shown in part (b). What are the final charge states of X and Y? Both X and Y are neutral. X is positive and Y is neutral. X is neutral and Y is positive. X is negative and Y is positive. Both X and Y are negative.

true

true or false: electrically neutral objects cannot exert an electrical force on each other, but they can exert a gravitational force on each other.