Electric charges that are different
attract each other.
repel each other. ****
exist in pairs.
do not interact.
Magnetic field lines around a bar magnet
are only perpendicular to the magnet.
spread out from one pole and curve around to the other. ****
cross back and forth over one another.
are perfectly straight.
Which of the following would decrease the magnetic field around a wire?
decreasing the current
reversing the poles of the wire
looping a section of the wire into a solenoid ****
increasing the current
What device transforms electrical energy into mechanical energy?
an electromagnet
an electric motor ****
a generator
a solenoid
A device used to open and close an electric circuit is a(n)
light bulb.
energy source.
switch. ****
resistor.
According to Ohm’s law, resistance is equal to voltage divided by
time.
conduction. ****
current.
potential.
In a series circuit with three bulbs,
the remaining two bulbs will go out if one bulb burns out.
the remaining two bulbs are not affected if one bulb burns out.
the brightness of the light bulbs does not change if more bulbs are added. ****
a switch is never used.
The strength of the force of gravity depends on
the masses of the objects and their speeds.
the masses of the objects and the distance between them.
the weight of the objects and their speeds.
the masses of the objects and their weights. ****
9. According to Ohm’s law, what is the resistance of a light bulb if the applied voltage is
9.0 V and the current is 0.30 amps?
0.033 ohms
2.7 ohms
30 ohms****
8.7 ohms
what are one three and 6
To determine the correct answer to question 1, we can use the basic knowledge of electric charges. Electric charges that are different repel each other. This can be understood through Coulomb's law, which states that the force between two electric charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them. Therefore, the correct answer is "repel each other."
For question 2, we can visualize the magnetic field lines around a bar magnet. The magnetic field lines spread out from one pole and curve around to the other. This can be observed using iron filings or a magnetic compass. Therefore, the correct answer is "spread out from one pole and curve around to the other."
To answer question 3, we need to understand how the magnetic field around a wire can be decreased. Decreasing the current flowing through the wire would reduce the strength of the magnetic field. Reversing the poles of the wire would not change the magnetic field. Increasing the current would actually increase the magnetic field. Looping a section of the wire into a solenoid would create a more concentrated magnetic field within the solenoid, but this would not decrease the magnetic field around the wire. Therefore, the correct answer is "decreasing the current."
Question 4 asks for the device that transforms electrical energy into mechanical energy. An electric motor is the correct device for this transformation. An electric motor converts electrical energy into mechanical energy by utilizing the interaction between magnetic fields and electric currents. Therefore, the correct answer is "an electric motor."
To answer question 5, we need to understand what device is used to open and close an electric circuit. A switch is the correct device for this purpose. A switch controls the flow of electrical current by either completing or interrupting the circuit. Therefore, the correct answer is "a switch."
Question 6 asks about Ohm's law, which states that resistance is equal to voltage divided by current. The resistance is directly proportional to the voltage and inversely proportional to the current. Therefore, the correct answer is "current."
For question 7, we need to understand the behavior of bulbs in a series circuit. In a series circuit, if one bulb burns out, the remaining bulbs will go out as well. This is because a series circuit is a single path for current flow, and if one component fails, the flow of current is interrupted. Therefore, the correct answer is "the remaining two bulbs will go out if one bulb burns out."
To answer question 8, we need to understand the factors that affect the strength of the force of gravity. The strength of the force of gravity depends on the masses of the objects and the distance between them. According to Newton's law of universal gravitation, the force of gravity is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between them. Therefore, the correct answer is "the masses of the objects and the distance between them."
For question 9, we can use Ohm's law to calculate the resistance of the light bulb. Ohm's law states that resistance (R) is equal to voltage (V) divided by current (I). Given that the applied voltage is 9.0 V and the current is 0.30 amps, we can divide the voltage by the current to find the resistance: R = V/I = 9.0 V ÷ 0.30 A = 30 ohms. Therefore, the correct answer is "30 ohms."
1, 3, 6 wrong.
7 is A.