Question regarding electric circuits and current

[950315]

Homework Statement

Referring to the electric circuit above, when the switch(S) turn on, the brightness bulb Q and Ammeter reading increases. so my question is, why? is it true that the S create another path way for current, then at the end of S, the electric current joins the electric current passed through bulb P , so the brightness of bulb Q increase? and why is the ammeter reading increase? Please correct me if my concept is wrong, thanks in advance.

Homework Equations

The Attempt at a Solution

 

[phinds]

Do you understand how current flows in a circuit? Do you understand the relationship between resistance and current?

 

[950315]

Do you understand how current flows in a circuit? Do you understand the relationship between resistance and current?

As how the current flows in a circuit, I am not that certain, but for the relationship between resistance and current, I understand it with the help of ohm's law

 

[phinds]

As how the current flows in a circuit, I am not that certain, but for the relationship between resistance and current, I understand it with the help of ohm's law

Good. THen how about you think of a better way of saying

S create another path way for current

and think about what that means for the current in the circuit.

 

[950315]

Good. THen how about you think of a better way of saying and think about what that means for the current in the circuit.

Sorry but, I don't get it..

 

[950315]

I just went through some reference book, and i got a conclusion. Correct me if i am wrong. The the switch S is closed, the current doesn't flow through P anymore, instead they only flow through the pathway S, as a result, the current doesn't undergo any resistance, and hence, the total Current is greater. In terms of equation, the resistance of S is negligible, so the effective resistance = 1/P + 1/0.00000000... , and the resultant resistance is very small. Am I right?

 

[phinds]

I just went through some reference book, and i got a conclusion. Correct me if i am wrong. The the switch S is closed, the current doesn't flow through P anymore, instead they only flow through the pathway S, as a result, the current doesn't undergo any resistance, and hence, the total Current is greater. In terms of equation, the resistance of S is negligible, so the effective resistance = 1/P + 1/0.00000000... , and the resultant resistance is very small. Am I right?

Yes, the bolded part is what I wanted to make sure you understand because this is what makes the total circuit resistance lower. As for specifics, I don't see any values on your diagram.

 

[950315]

Yes, the bolded part is what I wanted to make sure you understand because this is what makes the total circuit resistance lower. As for specifics, I don't see any values on your diagram.

Okay I finally got it, THANK YOU VERY MUCH DUDE !