Neco 2016 Physics Obj & Theory Answers | Neco Expo | Exam Runz

Unlimitedapps 11)
Tabulate
-Hard Xray-
i)high penetrating power
ii)short wave length
iii)produce high voltage
-soft Xray-
i)low penetrating power
ii)long wave length
iii)produced at low voltage
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8a)
Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes.
8b)
d=30cm,£=1.5*10^-5c r=30cm
30/100=0.3m
V=kE/r=9*10^9*1.5*10^-5/0.3
=13.5*10^4
=13.5*10^5/3
V=4.5*10^5
V=450kv
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5)
V1=700cm^3, T1=30dgree-census+273=303k, P1=606mmHg
V2=700-300=400cm^3, T2=47+273=320k
from general gas law
P1V1/T1 = P2V2/T2
606*700/303=P2*400/320
P2=606*700*320/303*400
P2=1120mmHg
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4a)
i)pulley
ii)the inclined plane
4b)
veiw the digrams
load------>fulcrum------>effort
eg-crowbar
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2a)
click here to veiw it digrams
i)distance covered=5m+10m=15m
ii)magnitude of his displacement
=a^2=b^2+c^2
x^2=5^2+10^2=25+100
x^2=125
x=sqr125
=5sqr5m
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1ai)
i)Rockets are used for space travels.
ii)Rockets are used for launching satellites into space
1aii)
i)Artificial Satellites are used to send signals for televisions,radio, etc
ii)Artificial satellites they are used for monitoring cloud patterns for a weather station
1b)
A propeller like piece called turbine is been rotated continuously by falling water from a dam, which then turns a metal shaft in an electric generator,which is the motor that produces electricity
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(12a) centre of gravity can be define as the point through which the line of action of the weight of the body always passes irrespective of the position of the body.
12b)
C.g = centre of gravity
:- v= u - gt
Of maximum height v=O - K
O= u-gt
For vertical component, U =uSin tita
Therefore O= usin tita- gt
gt =uSin tita
T=uSin tita/g
Where T is the time taken to maximum height
12c)
Taken moment about point A
Cwm = {60*10)+ (20*60)
Cwm=600+1200
Cwm=1800
Acwm = (20*40) + (R3 * 40)
Acwm=800+80R3
At equilibrium, Cwm=Acwm
1800=800+40r3
1800-800=40r3
1000=40r3
R3=1000/40
R3=25N
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13a)
dew point is the temperature at which the water vapour present in the atmosphere is just sufficent to saturate it
13b)
mist is formed as a result of condensed drops of moisture throughout the mass of cooled air. That is when water droplet in the air cool suddenly
13ci)
the plastic comb will acquire electric charges
13cii)
the plasic com can attract small pieces of paper due to the acquired charges.
13di)
area expansivity(

=2§
=2*1.2*10^-5
B=2.4*10^-5 1k
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13dii)
given that initial length=6cm
initial area A=6*6=36cm^2
rise in temperature =25k
linear expansivity=1.2*10^-5/k
area expansivity =2.4*10^-5/k
new area At=Ao(1+Btita)
At=36(1+2.4*10^-5*25)
At=36(1+ 60*10^-5)
At=36(1+0.0006)
At=36(1.0006)
At=36.0216
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15a )electrical potential is the work required to transfer a unit positive electric charge from an infinite distance to a given point against an electric field
15b)
veiw some digrams here
A metal rod can be made into a magnet by divided touch me thod as shown in the diagram above.
The metal rod is stroke at the middle with opposite pole end of two permanent magnets towards the opposite ends several times opposite polarity are then formed
15ci)
veiw the diagrams
VR=120v---->Vl=50v---->Vc=134.39v
220v,506z
15cii)
V^2=Vr^2+(Vl-Vc)^2
220^2=120^2+(50-Vc)^2
48400=14400+(50-Vc)^2
48400=14400=(50-Vc)^2
34000=(50-Vc)^2
50-Vc=sqr34000
50-Vc=184.39
-Vc=184.39-50
Vc=134.39v
;the potential difference acrross the capaitor is 134.39v
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# 2016-06-29 00:18 · (0)