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Under: (1)
Tabulate.
S/N; 1|2|3|4|5|
M|g; 40.0|35.00|30.00|25.00|20.00|
θ°; 41.80|35.70|30.00|24.60|19.47|
ϕ=(90-θ°); 48.20|54.30|60.00|65.40|70.53|
Cosϕ; 0.6665|0.5835|0.5000|0.4163|0.3333|
(1xi)
Slope , S=Δm|g/ΔCosϕ
=(40-20)g/0.6665-0.3333
S= 20g/0.3332=60.024g
(1xii)
K=s/2 =60.024g/g= 30.012g
(1xiii)
-Precautions-
(i) I avoided error due to parallax when reading from the protector
(ii) I ensured that the force board is firmly and correctly clamped to the retort stand
(1)
Graph

(1b)
Coming check by 8;10am
(3)
Tabulate
S/N; 1|2|3|4|5|
R/Ω; 2.00|4.00|6.00|8.00|10.00|
L/cm; 50.00|66.70|75.00|80.00|83.30|
B/Ω^-¹; 0.500|0.250|0.167|0.125|0.100|
Δ/cm; 1.000|0.499|0.333|0.250|0.200|
(3xiii)
Slope ,S=ΔB/Ω^-¹/ΔΔ/cm =0.5-0.1/1.0-0.2=0.4/0.8=0.5
Slope =0.5Ω^-¹/cm
(3xiv)
K=S^-¹= 1/5=1/0.5Ω^-¹/cm =2Ωcm
(3xv)
-precautions-
(i) I avoided error due to parallax when reading from the potentiometer
(ii) I ensured that the wire are tightly connected.
(3)
Graph

(3bi)
(i) potentiometer give exact value of potential difference while voltmeter draws apart of the current
(ii) potentiometer can be used for measuring the internal resistance of a cell which cannot be done with voltmeter
