See Chen Rong's answer to Athl's Secondary 4 Physics question

Chen Rong's answer to Athl's Secondary 4 Physics question.

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Utilise the V=IR and Q=IT formula.

Date Posted: 7 years ago

Comments 3 add a comment

Athl

7 years ago

Thanks. So to find the resistance of X, is it
I= 0.5-0.3333=0.167
R=1/0.167

Like this? Why we use the voltage of 1V, and not 2V(given by the battery)

Chen Rong

7 years ago

The voltage across both the 3ohm resistor and X is 1.0V, not the 2.0V across the battery. There has already been a 1.0v p.d drop across the 2.0ohm resistor, hence the the remaining potential drop across both the 3ohm resistor and X must be 1.0V as explained in the workings. The p.d across X and the 3.0ohm resistor must be the same at 1.0V as they are placed in parallel with one another.

Athl

7 years ago

Got it! Thanks so much.