physics obj
1-10 DAEDEBACCE
11-20 EADDEADCCB
21-30 DADEBBEAEC
31-40 DBBBBCBBDC
41-50 EBECDBCADD
51-60 BABCBDAADC
14ai.convex mirror
ii.because the image in convex mirror are
always the same regardless of the position of
the object.
14b
i.The mass per unit length of string increases
with the cross-sectional area,a thick string has
a greater mass per unit length than a thin
string
ii.f.=1/2L sqrt T/m
(1a) Force, unit is Newton(N)
(1b) Acceleration, Unit
is m/s^2
(1c) Velocity, Unit is m/s
(2a) It means that the substance
contains 10 units of elementary
particles and matter
(2b) weight of objects varies because of
- The spring used in spring
balance
-The acceleration due to gravity
(3a)- Kinetic enegy, A moving car is an
example
- Potential energy, bird at the
top of a tree is an example
(3b)Kinetic energy is the energy due to
motion
while potential
energy is the energy by virtue
of object
(15ai)
radioisotopes are elements with
atomic number of 82 and greater
and undergoes radiativitiy by
emission of certain radiation
(15aii)
-treatment of cancer
-sterilization of medical
equipments
(15bi)
The energy conversions that
take
place in the x-ray tube is from
radiant energy to kinetic energy
of the moving elections.
(15bii)
-by increasing the intensity of
light
-by exposure to higher
frequency
(15biii)
Two similaritiesbr />
-xrays and gamma rays are
electromagnetic radiation in
nature
-x-rays and gamma rays have
high penetrating power .
Two
differences-
-xrays are faster in speed than
gamma-rays
xrays are more
energetic than gamma-rays
(15c)
E2=-2.42 10^-19J
E0=-21.8*10^-19J
E=E2-E0
E=-2.42*10^-19-(-21.8^10^-19)
E=(-2.42 21.*10^-19 E=19.38*10^-19
E=1.938*10^-18j
(15Ci)
E=HF
1.98*10^-19=6.6*10^-34*F
FREQUENCY(F)= 19.38*10^-19
F=2.94*10^15
(15CII)
C=F*LAMDA
3*10^8=2.94*10^15*lamda
wavelenght=3*10^8/
(2.94*10^5)
=1.02*10^-7 lamda=1.02*10^-7m
1a) A Satellite is an artificial body placed in orbit
round the earth or
another planet in order to collect information
or for
communication.
1b) Cosmic (ii) Magnetic field
1c) The artificial satellite is first launched to
space which produces
visual signals to Tv stations and it’s further
transmitted or relayed
to individual house and hence, the 2014
Brazil world cup be viewed.
2b ) D = √(x2 – x1)^2 + (y2 – y1)^2
= √(-3-5)^2 + (-4-(-2))^2.
= √64+36
= 10unit
3a) Yes fractional force depend on the nature
of the surface
3b) Walking without fractional force
depending on the nature of the
surface, there would be slipping and skidding
4a) The work done is the area of the
rectangle
* Area of rectangle = L x B
Work done
(I) 2F^1 x d^1 = 2F^1d^1 ( ^
means raise to power)
Work done
(ii) F^1 x d^1 = F^1d^1
Difference in work done = 2F^1d^1 – F^1d^1
= F^1d^1Nm
4ii) Work done is defined as the minimum
energy required for electrons
to be liberated from the surface of a metal
when light is incident
onit
b) E= hf but C= F/|, F = C//| , E= hc//|
E= 5.5 x 10^-9J, /|= 6.6×10^-34 x
3×10^8/5.5 x 10^-9
/|=3.6×10^-17 {where J is joule, /| is
lander }
5a) 85 – x/ 50 – x = 100 – 0/40 – 0
4(85 – x) = 500 – 10x
-4x + 10x = 500 – 340
6x = 160
X= 26.67oc
6) V = 3x10m/s
From the diagram, T=12s(time taken to
complete one cycle)
6aii) V=F/|, F=1//| , /|= VT { where /| is
lander }
/|=3×10^3 x 12 = 3.6×10^4m
6aiii) F=1/t = 1/12= 0.083Hz
8a) E=2.0v, r=1ohm, R=?, V=1.92v
From E= I(R+r) also, V=IR, I=V/R
E= V/R(R+r)
2R= 1.92R + 1.92
2R – 1.92R = 1.92
0.08R = 1.92
R = 1.92/0.08 =24ohms
9a.) The basic unit of measure of electricity is
known as
the Watt.
One thousand Watts are called a kilowatt.
OR .the unit is kilowatt per
hour (kwh)/ def
1kwh is the energy consumed by power
consumption of 1kilowatt during 1hour.
(9b)Two Advantages At high voltages
(i)to ruduce the energy loss in long-distance
transmission,
(ii)also for greater efficiency during long
distance transmissiön.
two Advantages at Low Current
(i)to accomodate the use of low using
electrical appliances,
(ii) to promote even distribution of current.
10a) Natural radioactivity is the spontaneous
distingration of the
nucleus of an atom during which alpha
particle or beta particle,or
gamma rays or a combination of any or all
the three and heat (or
energy) are released.
While
Artificial Radioactivity this is an ordinary
material,not normally
radioactivr is made radioactive by bombarbing
it with radioactive
particles.
10b) Two Uses Of Radioisotopes.
i Radioisotopes are used in medicine as
radiotherapy.
ii. Radioisotopes are used in industry to study
defects in metals and
welded joints.
iii. Radioisotopes are used in geological
research for radio-dating
11a) Work function is defined as the minimum
energy required for
electrons to be liberated from the surface of
a metal when light is
incident on it
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