Question

Question 15 (3 points)
(9.40_Q15) The 9 volt battery is replaced with a 12 volt battery in a circuit with 12 Ω resistance. What happens to the current?

The current increases.


the current is unchanged


the current decreases.


Question 16 (3 points)
(9.40_Q16) What is the current in a circuit with a 6 volt battery and 1.5 Ω resistance?

0.25 amp


0.4 amp


4 amp


9 amp


Question 17 (3 points)
(9.40_Q17) A 6 volt battery is replaced with a 3 volt battery in a circuit with 3 Ω resistance. What happens to the current?

The current increases.


The current is unchanged


the current decreases


Question 18 (3 points)
(9.40_Q18) What kind of relationship exists between voltage and current?

a direct relationship


no relationship


an inverse relationship


Question 19 (3 points)
(9.40_Q19) Which affects which? Does voltage affect current or does current affect voltage?

voltage affects current


voltage and current have no relationship with each other


current affects voltage


voltage and current both affect each other.


Question 20 (3 points)
(9.40_Q20) A 12 volt battery is replaced with a 6 volt battery at the same time as the resistance of a circuit is reduced from 5 Ω to 2.5 Ω. What happens to the current?

The current increases


The current is unchanged


the current decreases


It is impossible to tell with the information provided.

Answer 1

Answer:

15. Current increases

16. 4 Amp

17. Current decreases

18. A direct relationship

19. voltage affects current

20. Current is unchanged

Explanation:

First you need to know about Ohm's Law. Ohm's law can be summarized in the formula:

$I = \dfrac{V}{R}$

where:

V = Voltage

I = Current

R = Resistance

As you can see, when you increase the voltage, the current increases as well. When you decrease the resistance, current increases as well. This means that voltage has a direct relationship with current, and current has an indirect relationship with resistance.

Voltage is the potential, or electrical potential energy that pushes the current along a circuit. THe current is the flow of energy, so it is actually the rate of electrical energy that goes through a point in a circuit over a period of time. The resistance is the resistive force, that the current goes through as it goes through a circuit.

Let's apply that to question 16:

$I=\dfrac{V}{R}$

Our given:

V = 6V

R = 1.5Ω

$I=\dfrac{6V}{1.5\Omega}=4A$

In question 17,just to show you, we can solve it and compare:

6 V battery and 3Ω resistance:

$I=\dfrac{6V}{3\Omega}=2A$

3 V battery and 3Ω resistance:

$I=\dfrac{3V}{3\Omega}=1A$

Current decreases from 2A to 1A.

Let's try it on Question 20:

12V and 5Ω

$I=\dfrac{12V}{5\Omega}=2.4A$

6V and 2.5Ω

$I=\dfrac{6V}{2.5\Omega}=2.4A$

There is no difference.