PHYSICS ANSWERS 2017
From www.042portal.blogspot.com
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NOTE:
Tita means θ
^ means Raise to power
Pie means π
/ (means) division or divide
2 whole no 3/4 means 2¾
* means
multiplication (×)
Sqr root means √
Proportional means ∝
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PHYSICS OBJ
1-10BBCADAAABB
11-20BBDCBDC-CD
21-30ABCDCCCDAC
31-40ACCBCDA-BC
41-50A-DDAADBDC
(1)
PLS SKETCH.
-decrease in height (h)
-increase in time (t)
-this shows that distance changes with time
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(2)
given that U=15ms^-1
R=U* sqr2h/g
h=20m
g=10
R=15*sqr2*20/10
R=15*sqr40/10
R=15*sqr4
R=15*2=30m
R=30m
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(3)
(i)Brownian motion
(ii)Atomic size
(iii)Expansion
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(4)
L1=14cm F1=4N,F2=6N
L2=4cm, Lo=?
Using hooke's law
4/14-Lo*6/4-Lo
4(4-Lo)=6(14-Lo)
16-4Lo=64-6Lo
-4Lo 6Lo=64-16
2Lo=48
Lo=48/2
Lo=24Cm
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5a)
i)force
ii)length
5b)
By increasing the density mosquitoes lavrva than the density of water
(6)
(i) Energy efficient - It is so far, the best light for interior lighting.
(ii) Low production cost (of tubes, not of the ballasts)
(iii) Long life of tubes
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(7)
(i) It is cheaper and quite easy to manufacture
(ii) It requires low voltage sources for it to function
(iii) It cannot be easily broken
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12ai)Nuclear fission is a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.
12aii)a)A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.
12aii)b)Boron rods are used in
nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
11a A dielectric is an electrical insulator that can be polorised by an applied electric field.
11aii) GIVEN: A = 9.6 * 10^-3 M^2
d = 2.25 * 10^4
Eo = 8.85 * 10^-12 F/m
Er = 900
C = /
using; C = EoErA/d
capacity, C = 8.85*10^-12 * 900 * 9.6*10^-3/2.25 * 106-4
C = 33984 * 10^-11
C = 3.3984 8 10^7 F
C =0.344F
11bi) A voltmeter has a higher resistance because it is designed to limit the flow of current to practically zero to avoid voltage drop or less across it.
11bii) combined resistance Rt
Rt = (400 * 400/400 400) (800 * 800/800 800)
Rt = 200 400
Rt = 600ohms
current supplied by battery = r/Rt
= 6/600
= 0.01A
voltage drop across the resistance = 200 * 0.01
=2V
therefore the voltage reading is 6 -2
= 4V
11c) Equivalent resistance is:
Rt = 2 2 (2*2/2 2)
Rt = 4 1
Rt = 5ohms
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Subscribe and get it earlier than its being posted here
NOTE:
Tita means θ
^ means Raise to power
Pie means π
/ (means) division or divide
2 whole no 3/4 means 2¾
* means
multiplication (×)
Sqr root means √
Proportional means ∝
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
PHYSICS OBJ
1-10BBCADAAABB
11-20BBDCBDC-CD
21-30ABCDCCCDAC
31-40ACCBCDA-BC
41-50A-DDAADBDC
(1)
PLS SKETCH.
-decrease in height (h)
-increase in time (t)
-this shows that distance changes with time
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
(2)
given that U=15ms^-1
R=U* sqr2h/g
h=20m
g=10
R=15*sqr2*20/10
R=15*sqr40/10
R=15*sqr4
R=15*2=30m
R=30m
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
(3)
(i)Brownian motion
(ii)Atomic size
(iii)Expansion
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
(4)
L1=14cm F1=4N,F2=6N
L2=4cm, Lo=?
Using hooke's law
4/14-Lo*6/4-Lo
4(4-Lo)=6(14-Lo)
16-4Lo=64-6Lo
-4Lo 6Lo=64-16
2Lo=48
Lo=48/2
Lo=24Cm
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
5a)
i)force
ii)length
5b)
By increasing the density mosquitoes lavrva than the density of water
(6)
(i) Energy efficient - It is so far, the best light for interior lighting.
(ii) Low production cost (of tubes, not of the ballasts)
(iii) Long life of tubes
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
(7)
(i) It is cheaper and quite easy to manufacture
(ii) It requires low voltage sources for it to function
(iii) It cannot be easily broken
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
12ai)Nuclear fission is a nuclear reaction in which a heavy nucleus splits spontaneously or on impact with another particle, with the release of energy.
12aii)a)A graphite reactor is a nuclear reactor that uses carbon as a neutron moderator, which allows un-enriched uranium to be used as nuclear fuel.
12aii)b)Boron rods are used in
nuclear reactors to control the fission rate of uranium and plutonium. They are composed of chemical elements such as boron, silver, indium and cadmium that are capable of absorbing many neutrons without themselves fissioning.
11a A dielectric is an electrical insulator that can be polorised by an applied electric field.
11aii) GIVEN: A = 9.6 * 10^-3 M^2
d = 2.25 * 10^4
Eo = 8.85 * 10^-12 F/m
Er = 900
C = /
using; C = EoErA/d
capacity, C = 8.85*10^-12 * 900 * 9.6*10^-3/2.25 * 106-4
C = 33984 * 10^-11
C = 3.3984 8 10^7 F
C =0.344F
11bi) A voltmeter has a higher resistance because it is designed to limit the flow of current to practically zero to avoid voltage drop or less across it.
11bii) combined resistance Rt
Rt = (400 * 400/400 400) (800 * 800/800 800)
Rt = 200 400
Rt = 600ohms
current supplied by battery = r/Rt
= 6/600
= 0.01A
voltage drop across the resistance = 200 * 0.01
=2V
therefore the voltage reading is 6 -2
= 4V
11c) Equivalent resistance is:
Rt = 2 2 (2*2/2 2)
Rt = 4 1
Rt = 5ohms
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