Required practicals

Question 1

RP- resistance in a wire
paper 1

Answer 1

-ammeter measures current
-voltmeter measures current
-ruler measures length of wire
-take a crocodile clip and attach it to the wire at position 0cm and 10 cm
-record the current and the voltage
-repeat this every 10 cm up to a m
-repeat this all 3 times
-discard anomalous results,calculate a mean
-calculate resistance by dividing the PD by current
-plot graph with wire length on x
resistance on ohms on y axis

Question 2

potential hazards of RP resistance in a wire

Answer 2

electrocution-to stop we ensure wires are not damaged
burns-turn off circuit as soon as reading are taken

Question 3

RP density of irregular objects
paper 1

Answer 3

density=mass/volume
-find the mass of the object by using a balance
-fill a eureka can with water and place a measuring cyclinder at the spout
-place the object into the water, causing the water to be displaced and flow out the spout
-measure the volume of water displaced, this is equal to the volume of the object
-substitute the values into the equation

Question 4

specific heat capacity
paper 1

Answer 4

-energy=mass x SHC x temp change
-measure mass of metal block or water with a balance
-put an electrical heater and thermometer in (if metal add a drop of water for better heat transfer)
-connect the heater to a power supply, with an ammeter in series and a voltmeter in parallel
-energy supplied= power x time
-record the initial temp, start the stopwatch and measure temp every 20s
-SHC = energy/ (mass x temp change)
-calculate total energy using final time and temp change,use these in the equation to calculate SHC
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Question 5

IV characteristics
paper 1

Answer 5

-connect component to a battery with an ammeter and variable resistor in series, and a voltmeter in parallel
-measure the current for varying PDS
-ohms law- V=IR
-rearranged R=V/I