Tuesday, December 17, 2013
Monday, October 28, 2013
Chapter 2 Quiz: Grade 11
Q01: Write down Pascal’s law. Mention one
of the uses of this law.
Pascal’s Law: When a fluid
completely fills a vessel and a pressure is applied to it at any part of the
surface, that pressure is transmitted equally throughout the whole of the
enclosed fluid.
pin = pout, Fin/Fout
= Ain/Aout
pin =
input pressure, pout = output pressure, Fin = input
effort,
Fout =
output load, Ain = area of intake piston, Aout = area of
outlet piston
1) Pascal’s law is very useful in
practical applications.
2) The constructions of hydraulic brakes
and hydraulic presses are based on Pascal’s law.
3) Hydraulic brakes are used in cars and
other road vehicles.
4) A hydraulic press is a very useful
machine. It is used for baling jute and for shaping steel and metal sheets. It
has numerous other uses, from the compression of soft metals into cups of
varying shapes to the pressing of automobile bodies.
2Q02: “Although Pascal’s law is not a
fundamental law, it is a very useful law for practical purposes.” Is this
statement correct? Discuss.
1) The statement is correct.
2) Pascal’s law is very useful in
practical applications.
3) The constructions of hydraulic brakes
and hydraulic presses are based on Pascal’s law.
4) Hydraulic brakes are used in cars and
other road vehicles.
5) A hydraulic press is a very useful
machine. It is used for baling jute and for shaping steel and metal sheets. It
has numerous other uses, from the compression of soft metals into cups of
varying shapes to the pressing of automobile bodies.
2Q03: Write down Archimedes’ principle.
2Q06: What will be the effect on the
mercury column if the glass tube used has (a) a smaller internal diameter (b) a
slightly bigger internal diameter?
1)
The height of mercury column depends only on the atmospheric pressure
outside the tube.
2)
It does not depend on cross-sectional area.
3)
So there will be no effect for both cases.
4)
The mercury column will remain at 76 cm.
2Q07: Will the mercury column be higher or
lower than 76 cm when the whole up of the barometer is taken to a high mountain
top?
1)
Less,
2)
because the pressure of the surrounding air is less than that at sea
level.
3)
This is because at greater heights air is thin.
2Q08: Why is mercury used in a barometer
rather than water?
1)
The
pressure exerted by the atmosphere is the same for water and mercury.
2)
pHg
= pW (Hg = mercury, w =
water)
3)
rHg g hHg
= rW g hW
4)
hw = (rHg hHg)/rw = 13.6 ´ 76 = 1033.6 cm = 10.336 m
5) Density of mercury is much larger
than that of water.
6) If mercury is used only 76 cm (about
1 m) of tube is needed.
7) If water is used 10.336 m (more than
10 m) of tube is needed.
8) Water barometer is much longer than
mercury barometer.
9) Thus, mercury is used in a barometer
rather than water.
2Q09(a): What is the effect on the vertical height of the mercury
column in a barometer of using a wider glass tube?
1)
The
vertical height of the mercury column in a barometer only depends on the
atmospheric pressure outside the tube.
2)
The
vertical height of the mercury is independent of the diameter or the
width of the tube.
3)
The
pressure in a liquid doesn’t depend on the container angle or width.
4)
Using
a wider glass tube will not change the height of the mercury column.
5)
The
height of the mercury column will remain at 760 mm.
2Q09(b): What is the effect on the vertical height of the mercury
column in a barometer of pushing the tube further into the bowl?
1)
The
vertical height of the mercury column in a barometer only depends on the
atmospheric pressure outside the tube.
2)
Pushing
the tube further into the bowl will not change the height of the mercury column
as long as the vertical height of the mercury column exceeds 760 mm.
2Q09(c): What is the effect on the vertical height of the mercury
column in a barometer of tilting the glass tube at an angle?
1)
The
vertical height of the mercury column in a barometer only depends on the
atmospheric pressure outside the tube.
2)
The
vertical height of the mercury does not depend on the tilt of the column as
long as the vertical height of the mercury column exceeds 760
mm.
2Q09(d): What is the effect on the vertical height of the mercury
column in a barometer of taking the barometer to the top of the mountain?
1)
The
vertical height of the mercury column in a barometer only depends on the
atmospheric pressure outside the tube.
2)
The
pressure at the top of the mountain is less than 760 mm Hg because the pressure
of the surrounding air is less than that at sea level.
3)
This
is because at greater heights air is thin.
4)
So
the height of the mercury column will be lower than 760 mm.
2Q14: Give the approximate value of atmospheric pressure at sea
level in (i) Pa
(ii) mm Hg (iii) atm?
(a) 105 Pa (b) 760 mm Hg (c) 1 atm
2Q14: Explain why the thickness of the dam increases downwards.
1)
The
thickness of the wall of the dam increases downwards because the deeper it is,
the greater the water pressure.
2)
A
thicker wall is required to withstand a greater pressure.
2Q15: A beaker containing water and placed on a pan is balanced by
the weight which is in the other pan of the balance. Explain what will happen
if a man immersed his finger in the water without touching the beaker.
1) If a man immersed his finger in the
water, there would be upward thrust on the finger.
2) Some water has to be displaced for
the finger according to the Archimedes’ principle.
3) This displaced water will show
unbalance of the balance.
2Q17: Steel will float in liquid (mercury)
but sink in water. So how does a steel ship manage to float in water?
R There is far more air in a ship than
steel, (because a ship is hollow and contains air), so the average density of
the ship is less than that of water.
2Q26: Why is it easier to float in the sea
than in a swimming pool?
1) The density of sea water is greater
than that of fresh water.
2) The upward thrust is directly
proportional to the density of the liquid. (Fup = rgV, Fup = upward thrust, r = density of liquid).
3) The upward thrust of sea water is
greater than that of the water in the swimming pool.
4) Thus, it is easier to float in the
sea than in a swimming pool.
Sunday, October 20, 2013
Grade 11 Physics Chapter 1: Quiz
Q01: Define “power”
The rate of doing work is defined as
power.
Q02: Explain why power is a useful concept in practical works.
1)
Power is the rate of doing work. (P = W/ t)
2)
The greater the power, the more work it can do in a certain period of
time.
3)
Car engines, water pumps, refrigerators, air conditioners and electric
bulbs, fluorescent tubes, are classified according to their rated powers.
4)
Thus power is a useful concept in practical works.
Q03: Which is more advantageous: to
pay wages according to the amount of work done or according to power?
1) Power can give only the rate of work
done.
2)
The wage depends on amount of work done.
3)
To pay wages according to the amount of work done is more advantageous.
Q04: Since power has only ...(1)... and
no direction, it is a ..(2)... The SI unit for power is ..(3)... The powers of
motors and engines are also expressed in ..(4).. which is a unit in British
engineering system.
(1) magnitude (2) scalar (3)
watt (W) (4) horse power (hp)
Q05: Fill in the blanks. Since power
has only ...(1)... and no direction, it is a ..(2)... The SI unit for power is
..(3)... The powers of motors and engines are also expressed in ..(4).. which
is a unit in British engineering system.
(1) magnitude (2) scalar (3) watt (W) (4)
horse power (hp)
Q06: Why is a high power machine used
to do a lot of work quickly?
1) P = W/ t, where P = power, W = work
done, t = time
2) If work is constant, P µ 1/t
3) If time is small (quick), power must
be large (high power).
Q07(a): When a large
power machine and a small power machine are operated for the same period of
time, will the large power machine consume less fuel?
1) No.
2) P = W/ t, where P = power, W = work
done, t = time
3) If time is constant,
4) If power is large, work done is also
large.
5) To do a larger work, a larger energy
or fuel is needed.
Q07(b): Can a lot of work be done only if a large power machine is
used?
1) No.
2) P = W/ t, where P = power, W = work
done, t = time
3) If work is constant, P µ 1/t
4) If power is small, time must be
large.
5) So a small power machine may be used
for as long as necessary.
Q07(c): A lot of
work can be done by operating a small power machine for as long as necessary.
Why?
1) P = W/ t where P = power, W = work done, t = time
2) If work is constant, P µ 1/t
3) If power is small, time must be
large.
Friday, October 18, 2013
All Definitions for Grade 11 Physics
1.
Work Done
2. Power
3. Watt
4. 1 watt
5. Simple Machines
6. Hydraulic System
7. Lever
8. Machine
9. Mechanical Advantage (MA)
10.
Velocity
Ratio (VR)
11.
Efficiency
12.
Input
work
13.
Output
work
14.
Perfect
Machine
15.
Elasticity
16.
Elastic
Limit
17.
Hooke’s
Law
18.
Stress
19.
Strain
20.
Pressure
21.
pascal.
22.
Atmospheric
pressure
23.
Barometer
24.
Torricellian
vacuum
25.
Standard
Atmospheric Pressure
26.
Sucking
27.
Syringe
28.
Manometer
29.
Buoyancy
30.
Archimedes’
Principle
31.
Hydrometer
32.
Pascal’s
Law
33.
Heat
Conduction
34.
Thermal
conductivity
35.
Temperature
Gradient
36. Heat Current
37.
Heat
Convection
38.
Heat
Radiation
39.
The
best absorber
40.
Black
Body
41.
Total
Emissive Power
42.
Stephan-Boltzmann’s
Law
43.
Emissivity
(e)
44.
Kinetic
Theory of Gas
45.
Brownian
motion
46.
Progressive
Waves
47.
Stationary
Waves
48.
Nodes
49.
Antinodes
50.
Amplitude
51.
Wavelength
52.
Longitudinal
wave
53.
Oscillation
54.
Transverse
wave
55.
Frequency
56.
Hertz
57.
Wave
equation
58.
How
a stationary wave is obtained
59.
Harmonics
60.
Fundamental
or First Harmonic
61.
Forced
motion
62.
Resonant
frequency
63.
Beat
64.
Intensity
of a Wave
65.
Diffraction
66.
Refraction
67.
Light
68. Newton
69.
Huygens’
Wave Theory of Light
70.
Refraction
of Light
71.
Incident
ray
72.
Refracted
ray
73.
Normal
74.
Angle
of Incidence
75.
Angle
of Refraction
76.
Principle
of reversibility of light
77.
Laws
of Reflection
78.
Laws
of Refraction
79.
Snell’s
Law
80.
Refractive
Index
81.
Refractive
index using Snell’s laws
82.
Absolute
refractive index
83.
Critical
angle
84.
Internal
reflection
85.
Total
Internal Reflection
86.
Prism
87.
Thin
prism
88.
Angle
of prism
89.
Angle
of Deviation (D)
90.
Lateral
displacement
91.
Light
pipe
92.
Optical
fibres
93.
Primary
light colours
94.
Secondary
light colours
95.
Spectrum
96.
Dispersion
97.
Lens
98.
Thin
lens
99.
Converging
or Convex lens
100.
Diverging
or Concave lens
101.
Sign
Convention for Radius of Curvature of Lens
102.
Real
image
103.
Virtual
image
104.
Principal
Axis
105.
Centre
of the Lens
106.
Principal
Focus of a Convex Lens
107.
Focal
Length
108.
Principal
Focus of a Concave Lens
109.
Principal
Rays for Lens
110.
Lens
equation
111.
Lens
Formula
112.
Lens-makers’
equation/formula
113. Sign
Convention for Lenses
114.
Magnification
115.
Dioptric
power of lens (or) Power of Lens
116.
Unit
power or Dioptre
117.
The
Common Defects of Vision
118.
Longsightedness
119.
Longsightedness
or Hyperopia
120.
Shortsightedness
121.
Shortsightedness
or Myopia
122.
Near
point of the eye
123.
Magnifying
Glass (OR) Simple Microscope
124.
Magnifying
Power
125.
Compound
Microscope
126.
Telescope
127.
Terrestrial
Telescope
128.
Binoculars
129.
coulomb
130.
Electric
charge
131.
Coulomb’s
Law
132.
Electric
Field
133.
Electric
Field Intensity
134.
Electric
field intensity from Coulomb's law
135.
Electric
Lines of Force
136.
Non
Uniform Electric Field
137.
Uniform
Electric Field
138.
Lightning
conductor
139. Electric
potential energy
140.
Electric
Potential
141.
Unit
of electric potential
142.
1
volt
143.
volt
144.
Voltage
145.
Electric
Potential Difference
146.
The
Unit of Electric Potential Difference
147.
The
Electric Potential due to a Point Charge
148.
Equipotential
Surface
149.
Conductors
150.
Insulators
151.
Capacitor
152.
The
Charge of the Capacitor
153.
The
Potential Difference of the Capacitor
154.
Capacitance
of a Capacitor
155.
1
farad (F)
156.
Electric
capacity
157.
Surface
Charge Density
158.
Dielectric
Constant
159.
Capacitor
in series
160.
Capacitor
in parallel
161.
Electric
Current
162.
Electron
current
163.
Conventional
current
164.
1
ampere
165.
ampere
166.
Ohm’s
Law
167.
Resistance
168.
Resistance
of a Conductor (using Ohm’s law)
169.
ohm
170.
The
resistivity of the conductor
171.
Parallel
circuit
172.
Series
circuit
173.
Electromotive
Force
174.
Unit
of Electromotive Force
175.
Available
Voltage
176.
Ammeter
177.
Voltmeter
178.
Series
Aiding
179.
Series
Opposing
180.
Electrical
Energy
181.
Electrical Power
182.
kilowatt-hour
183.
Joule’s Law of Electricity and Heat
184.
Fuse
185.
Damaged
insulation
186.
Overheating
of cables
187.
Damp
conditions
188.
Magnet
189.
Bar
magnet
190.
Magnetic
Field
191.
The
Right Hand Rule
192.
Right-hand
(wire) rule
193.
Solenoid
194.
Fleming’s
Left-hand Rule
195.
Torque
196.
Couple
197.
Electromagnet
198.
Shunt
199.
Electromagnetic
induction
200.
Induced
current
201.
Faraday's Law of Electromagnetic Induction
202.
Magnetic
Flux
203.
Lenz's Law
204.
Alternating
currents
205.
Direct
Current
206.
Transformer
207.
Thermionic
Emission
208.
Diode
Characteristics
209.
Triode
Characteristics
210.
Semiconductors
211.
Positive
Hole
212.
n-type
semiconductor
213.
p-type
semiconductor
214.
P-N
Junction
215.
P-N
Junction Diode
216.
Forward
Biased
217.
Reverse
Biased
218.
Rectifier
219.
Transistor
220.
The
Advantages of Transistors
221.
pnp
transistor
222.
npn
transistor
223.
Electronic
Circuit
224.
Logic
Gates
225.
Demodulation
226.
Input
device
227.
Output
device
228.
Data
Storage Device
229.
Operating
System Software
230.
Application
Software
231.
Atom
232.
Atomic
mass
233.
Atomic
mass number
234.
Mass
number
235.
Atomic
number
236.
Atomic
mass unit (amu or u)
237.
Neutron
number
238.
Neutron
239.
Nucleon
240.
Nucleus
241.
Nuclide
242.
Proton
243.
Proton
number
244.
Decay
(radioactive)
245.
Decay
rate
246.
Decay
time
247.
Isotopes
248.
Isomer
249.
Electron
250.
electron-volt
(eV)
251.
Ion
252.
Ionizing
radiation
253.
Irradiate
254.
MeV
255.
Neutrino
256.
Nuclear
binding energy
257.
Radioactivity
258.
Radioactive
Material
259.
Cathode
Rays Tube
260.
CRO
261.
Electromagnetic
radiation
262.
Cathode
Rays
263.
The
Properties of Cathode Rays
264.
X-rays
265.
x-radiation
266.
Production
of x-rays in Laboratory
267.
Properties
of X-rays
268.
Uses
of X-rays
269.
Alpha
Rays
270.
Alpha
particle (alpha radiation, alpha ray)
271.
Properties
of Alpha Rays
272.
Beta
Rays
273.
Beta
particle (beta radiation, beta ray)
274.
Properties
of Beta Rays
275.
Gamma
Rays
276.
Properties
of Gamma Rays
277.
Activity
278.
becquerel
(Bq)
279.
curie
(Ci)
280.
Half-Life
281.
Tracers
282.
Detector
283.
Nuclear
reactor
284.
Parent
nuclide
286.
Photomultiplier
287.
Pion
288.
QCD
289.
QED
290.
Quark
291.
rad
(Radiation Absorbed Dose)
292.
Radioactive
dating
293.
Radioactive
waste
294.
Radioisotope
295.
Radionuclide
296.
rem
(röntgen equivalent man)
297.
Residual
strong force
298.
röntgen or roentgen (R)
299.
Scaler
300.
Scintillation
counter
301.
Scintillator
302.
Secular
equilibrium
303.
Shielding
304.
sievert
(Sv)
305.
Source
306.
Stable
307.
Standard
Model
308.
Strong
interactions
309.
Symmetry
310.
Thermal
energy
311.
Transmutation
312.
Ultraviolet
radiation
313.
Van
de Graaff Accelerator
314.
Weak
interaction
315.
Nuclear
fission and Chain Reaction
316.
Carbon
dating
317.
Dating
rocks
318.
Radiotherapy
319.
Uses
of Tracers
320.
Energy
and Mass
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