required practicals

Question 1

investigating factors affecting resistance:

Answer 1

connect a 1.5 V cell , switch, ammeter, crocodile clips attached to test wire on meter ruler, and voltmeter connected across test wire.
-Connect the crocodile clips to the resistance wire, 100 centimetres (cm) apart.
-Record the reading on the ammeter and on the voltmeter.
-Move one of the crocodile clips closer until they are 90 cm apart.
-Record the new readings on the ammeter and the voltmeter.
-Repeat the previous steps reducing the length of the wire by 10 cm each time down to a minimum length of 10 cm.
-Use the results to calculate the resistance of each length of wire by using R = V/I, where R is resistance, V is voltage and I is current.
Plot a graph of resistance against length for the resistance wire.

From the graph it can be seen that the longer the piece of wire, the higher the resistance. Resistance is directly proportional to length as the graph gives a straight line through the origin.

Question 2

iv characteristics practical

Answer 2

battery, variable resistor, ammeter connected in line with component, component with voltmeter going across it
Adjust the variable resistor until the voltmeter reads 1 V.
Record the readings on the ammeter and on the voltmeter.
Adjust the variable resistor to increase the voltmeter reading to 2 V.
Record the new readings on the ammeter and the voltmeter.
Repeat steps 4 and 5, increasing the voltage by 1 V each time, until the voltmeter reads 12 V.