NECO – PHYSICS – PRACTICALS – ANSWER

3 )
ii) To= 2 . 00V
3 v )
Tabulate
S/ N – | 1 | 2 | 3 | 4 | 5 |
R ( n ) – | 2 | 3 | 4 | 5 | 6 |
V ( v ) – 2 . 10| 2 . 30| 2 . 40| 2 . 50| 2 . 60|
R ^ – 1 ( n ^ – 1 ) – | 0 . 500 | 0 . 333 | 0 . 250 | 0 . 200 | 0 . 167 |
V ^ – 1 ( V ^ – 1 ) – | 0 . 476 | 0 . 435 | 0 . 417 | 0 . 400 | 0 . 385 |
3 bii )
CLICK HERE FOR NO . 3 GRAPH
3 vii )
Slope
= Δv ^ – 1 / ΔR – 1
= 0 . 5 – 0 . 355 / 0 . 6 – 0
= 0 . 145 / 0 . 6
S= 0 . 242
Intercept
C = 0 . 355 v ^ – 1
3 aviii )
K = S/ C
K = 0 . 242 / 0 . 355
K = 0 . 68
3 ix )
i ) I ensured that the terminals were firmly tight to prevent partial contact
ii) I avoided parallax error when taking reading from the voltmeter .
3 bi)
i ) temperature of wire
ii) cross- sectional area of wire
iii ) length of wire
iv ) nature of wire
3 bii )
effective E . M . F = 2 V ( parallel connection )
effective internal resistance = rxr/ r + r = r / 2 n
current I = 0 . 8 A
external Resistance R = 2 n
using
E = I ( R + r )
2 = 0 . 8 ( 2 + r / 2 )
2 . 5 = ( 2 + r / 2 )
2 . 5 – 2 = r / 2
0 . 5 = r / 2
r = 0 . 5 x2 = 1 n
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2 )
Tabulate
Cos @ – | 75| 65| 55| 45| 35|
MO ( cm) – | 1 . 1 | 2 . 0 | 2 . 5 | 3 . 4 | 3 . 9 |
NO ( cm) – | 6 . 2 | 6 . 4 | 6 . 6 | 6 . 8 | 7 . 2 |
H = MO / NO – | 0 . 177 | 0 . 313 | 0 . 379 | 0 . 500 | 0 . 542 |
Cos @ – | 0 . 2588| 0 . 4226| 0 . 5736| 0 . 7071| 0 . 8192|
2 bi)
Snell ‘ s law is a formula used to describe the relationship between the angles of incidence and refraction , when referring to light or other waves passing through a boundary between two different isotropic media , such as water, glass, or air .
i ;e sini / sini = n
were n is known as refractive index
2 aix)
CLICK HERE FOR NO . 2 GRAPH
From the graph
Slope
S = Δcostita / ^ ΔH
= 0 . 75- 0 . 45/ 0 . 5 – 0 . 3
= 0 . 3 / 0 . 2
= 1 . 5
2 bii )
given refractive index of glass = 1 . 5
i ;e a N g = 1 . 5 ( from air to glass)
sin C / sin 90= gNa
sinC / sin 90= 1 / aNg
sinC / 1 = 1 / 1 . 5
since = 0 . 6667
C = sin ^ – 1 ( 0 . 6667)
critical angle for glass,C = 42degree
2 biii)
i ) I Ensured that the pins were vertical
ii) I Avoided parallax error when reading protractor .
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