ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: kenhung123 on April 03, 2010, 06:59:24 pm
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I'm unsure why a switch when closed and connected in parallel to a resistor would close off the current flowing through the resistor.
What exactly are the effects of a switch besides cutting off the flow of current when opened?
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When the switch is closed, it basically gives an alternative pathway of less resistance for the current to flow.
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But say like 2 resistors connected in parallel, one with high and one with low resistance, does that mean no current flows through the higher resistance?
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But say like 2 resistors connected in parallel, one with high and one with low resistance, does that mean no current flows through the higher resistance?
no, there is current flowing in the higher resistor but not as much compared to the smaller resistor.
say u supply 12V and u have a 6 ohm and a 8 ohm resistor. the total current flowing would be 3.5 A. u can use ohms law to prove that 2 A flows through the 6 ohm resistor and ~1.5A through the 8 ohm resistor. u can also use ratios.
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Hmm then how does the 0 resistance switch attract all current?
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Hmm then how does the 0 resistance switch attract all current?
not all but most, usually results in a short circuit when u have say a 10 ohm and a 10000 ohm resistor.
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Ah I get it now! Because I=V/R and since in parallel they share the same V but varying the R would alters the current. The larger the R the lower the current. In the case of the switch with very less resistance (close to 0), it will have all the current.