Procedure
i) Set up the circuit as shown , Fixing the 4.5 volts DC Power supply , variable resistance , one multimeter as ammeter and the other as voltmeter , the two unknown resistors on the circuit board
ii) to measure the first unknown resistance Rx1 , S1 must be on , S2 is off and S3 can be off or on , then by changing the value of variable resistance , the current changes and the potential difference changes . write down the readings of the ammeter and the voltmeter . take different readings .
iii) to measure the second unknown resistance Rx2 , S1 must be off , S2 is on and S3 can be off or on , then by changing the value of variable resistance , the current changes and the potential difference changes . write down the readings of the ammeter and the voltmeter . take different readings .
iv) to verify the law of series combination of resistances , S1 and S2 must be off and S3 is on ,then by changing the value of variable resistance , the current changes and the potential difference changes . write down the readings of the ammeter and the voltmeter . take different readings .
v) to verify the law of parallel combination of resistances , S1 and S2 must be on and S3 is off , then by changing the value of variable resistance , the current changes and the potential difference changes . write down the readings of the ammeter and the voltmeter . take different readings .
table (1) shows the different cases of the resistors combination
