1. technology and computing

Review Questions for Physics (162- ‫ تحض‬-3)
Fluid Mechanics
Ch. 13 Mechanics of Nonviscose Fluids
1. According to Archimedes` principle; an object floated or submerged in a fluid
experiences:
a) A downward force that equals the weight of the displaced fluid.
b) An upward force that equals the volume of the displaced fluid.
c) An upward force that equals the weight of the displaced fluid.
d) A horizontal force that equals the weight of the displaced fluid.
2. According to Archimedes’s principal the volume of the displaced fluid
……………………….the volume of the immersed object.
a) is smaller than.
b) is larger than.
c) is equal to.
d) has no relation with.
3. When an object is suspended in a fluid by a string, the tension in the string is reduced
by ………...
a) the viscosity force
b) the volume of the displaced fluid
c) the weight of the immersed body
d) the weight of the displaced fluid
4. The density of ice is 920 Kgm-3 while that of sea water is 1025 Kgm-3, what fraction of an
iceberg is submerged?
a) 0.89
b) 0.98
c) 8.9
d) 9.8
5. A water pipe leading up to a hose has a radius of 2 cm. water leaves the hose at a rate
of 4 litres/minute. Find the velocity of the water in the pipe?
a) 0.005 m/s
b) 0.05 m/s
c) 0.5 m/s
d) 5 m/s
6. If a stream of fluid has its cross-sectional area halved in a certain region, its average
velocity is ………………..
a) halved
b) doubles
c) constant
d) decreased
7. The pressure at the same depth at two places in a fluid at rest is …………..
a) different
b) the same
c) the atmospheric pressure.
d) not related
8.
When a person, in an erect position, experiences an upward acceleration (a),thus the
pressure in the brain PBrain will be reduced as follow:
a) P Brain = P Heart - ρ (g + a) ( hBrain + hHaert)
b) P Brain = P Heart + ρ (g + a) ( hBrain - hHaert )
c) P Brain = P Heart - ρ (g + a) ( hBrain - hHaert )
d) P Brain = P Heart + ρ (g - a) ( hBrain - hHaert )
9. In the reclining position, the small pressure drop between the heart and feet or brain is
due to the…………… forces.
a) gravitational
b) viscous
c) electrical
d) chemical
10. The manometer is a device used to measure……………………..
a) the gas pressure and can be used also to measure liquid pressure.
b) the gas humidity
c) the gas density
d) the gas temperature
11. Select the correct equation that correlates between the pressures PFeet, and PHeart or
PBrain for adults in the standing position.
a) PF = PH + ρ g (hBrain + h Heart )
b) PF = PH + ρ g hFoot
c) PF = PH + ρ g hHaert
d) PF = PH + ρg hBrain
Ch. 14 Viscose Fluid Flow
12. The aorta of an average adult human has a radius of 1.2 x 10 -2 m. If the flow rate of
blood is 10-4 m3s-1, the flow resistance over 0.3 m distance is:
(η = 2.084 x 10 -3Pa s)
-3
a) 56.8 kPa s m
b) 46.8 kPa s m-3
c) 66.8 kPa s m-3
d) 76.8 kPa s m-3
13. The centripetal acceleration is always …………………. the gravitational acceleration, g.
a) greater than
b) less than
c) equal to
d) not related to
14. A protein of density 1.3 x 103kg m-3 has a sedimentation velocity of 10-5 ms-1 in a
centrifuge with acceleration 105 ms-2. At this velocity the drag force is 2.07 x 10-16 N.
Find the molecular mass of the protein?
(1u = 1.66 x 10-27 kg, ρo=103kg m-3)
a) 5.4×106u
b) 5.4×105u
c) 4.5×106u
d) 4.5×105u
15. What is the net resistance of the 4.73 X 107 capillaries in the mesenteric vascular of
a dog, if the radius of a single capillary is 4 X 10-6 m and its length is 10-3 m.viscosity
of the blood is 2.084 X 10-3 Pa s
a) 4.38 X 1013 k Pa S m-3
b) 2.073 X 1013 k Pa S m-3
c) 1.326 X 1013 k Pa S m-3
d) 4.38 X 105 k Pa S m-3
16. Find the drag force at terminal velocity in air of a spherical dust particle of radius
10-5 m and density of 2 X 103 kg m-3 at 20o C. viscosity of air is 1.81 X 10-5 Pa s
(density of air is neglected ).
a) 8.23 X 1011 N
b) 2.44 X 1012 N
c) 44.2 X 1012 N
d) 23.8 X 1013 N
17. When the speed of moving object in a fluid increases slightly the high speed drag
force is directly proportional to its ……………………….
a) velocity.
b) viscosity.
c) square velocity.
d) square viscosity.
18. In a mixture of two kinds of solutes, the larger molecules will sediment
…………………….the smaller one.
a) faster than
b) slower than
c) equal to
d) in opposite direction to
19. The effective weight of a rotating object (we) of mass m is given by ……………………….
a) we=mωr
b) we = mg
c) we=m2(g-ar)
d) we=m(g-ar)
Ch. 15 Cohesive Forces in Liquids
20. A rubber balloon is inflated to a radius of 0.2 m. The pressure inside is 1.002×105Pa, and
the pressure outside is 105 Pa, the tension in its wall is:
a) 5 N/m
b) 10 N/m
c) 15 N/m
d) 20 N/m
21. The unit of surface tension is ……………………….
a) N/m2
b) N/sec
c) N/m3
d) N/m
22. The specific form of Laplace's law depends on ……………………….
a) the volume of fluid.
b) the mass of the fluid.
c) the shape of the closed surface
d) the molecular structure.
23. Laplace's law relates the pressure difference across a closed elastic membrane or
liquid film to…………
a) the volume of fluid
b) the tension.
c) the shape of the closed surface
d) the projected area of the closed surface.
24. Laplace 's law for a spherical bubble takes the form:……………………..
a) Pi - Po = 2γ/r
b) Pi - Po = γ/2r
c) Pi - Po = 4γ/r
d) Pi - Po = γ/r
25. The pressure inside a soap bubble is……………………….the atmospheric pressure.
a) has no relation to
b) smaller than
c) equal
d) larger than
26. If the surface tension (γ) of a liquid = 7.28x10-2 Nm-1, and the length of the wire is
0.2 m, the total weight will the liquid support in the apparatus of the U-shaped loop
is ……………………….
a) 1.20x10-1 N
b) 2.90x10-2 N
c) 4.20x10-3 N
d) 6.46x10-4 N
Ch. 17 Direct Current
26. Once the capacitor is fully charged the current ………………
a) increases
b) decreases
c) stopped
d) varies
27. The …………………………in the circuit steadily diminish, reaching very small values after
few time constant
a) resistance
b) charge and the current
c) capacitance
d) thermistor
28. Each cycle in the human heart begins with an electrical ………………pulse from a group
of nerve fibers.
a) pace maker
b) ground fault interrupters
c) thermistor
d) strain gauge
29. Between 10 and 20 mA will paralyze some muscles and prevent person from
releasing ………………
a) fuse
b) circuit breaker
c) water Pipes
d) conductor
30. About 18 mA contracts………………muscles and causes breathing to stop.
a) heart
b) eye
c) chest
d) knee
31. ………………are used to study changes in living cells to control various materials are
added to the cellular environment.
a) Capacitances
b) Resistance measurements
c) Pacemaker
d) Strain Gauges
32. Electrophoresis is an efficient technique for separation and analyzing the mixtures of
………………found in human blood and in other biological materials.
a) proteins
b) lipids
c) carbohydrates
d) minerals
33. In a circuit containing a resistance, a capacitor, and an EMF, C = 2 µF, R = 10 3 Ω, and
EMF = 6 V. The final charge on the capacitor will be………………
a) 33 x 10 -6C
b) 12 x 10 -6C
c) 6 x 10 -6C
d) 2 x 10 -6C
34. In a circuit containing a resistance, a capacitor, and an EMF, C = 2 µF, R = 10 3 Ω, and
EMF = 6 V. The initial current in the circuit will be………………
a) 3 x 10 -3 A
b) 6 x 10 -3A
c) 12 x 10 -3A
d) 33 x 10 -3A
35. In a circuit containing a resistance, a capacitor, and an EMF, C = 2 µF, R = 103 Ω, and
EMF = 6 V. The time constant in the circuit will be………………
a) 2 x 10 -3 s
b) 6 x 10 -3 s
c) 15 x 10 -3 s
d) 30x 10 -3s
36. protein molecule has mass of thousands of atomic mass with a few times of Large
electronic charge. It, with respect to small mass and charge molecule, will drift in an
electric field :
a) the same
b) much more quickly
c) much more slowly
d) as small ions
37. The average adult can detect a current as small as………………
a) 100 mA
b) 20 mA
c) 18 mA
d) 1 mA
38. The small resistance in the artificial pacemaker circuit ………………
a) make the discharge slowly
b) make the discharge constant
c) accelerate the charging process
d) stabilize the current on the capacitor
39. A device called ………………is installed in the ground wire of three-wire circuits. If the
current exceeds 5 mA, this device opens the circuit.
a) all-insulated construction
b) ground-fault-interrupter
c) thermistor
d) fuse
Ch. 18 Nerve Conduction
40. The short space between schwan cells called ………………where ionic transfers occur.
a) dendrite
b) synapses
c) node of ranvier
d) cell body
41. Diffusion of ions from higher to lower concentration regions is due to their………………
a) equilibrium potential
b) random thermal motion
c) active transport
d) impermeability of cell membrane
42. In passive flow ………………
a) both Na+ and K+ flow into the cell
b) both Na+ and K+ flow out of the cell
c) Na+ flows out of the cell while K+ flows into the cell
d) Na+ flows into the cell while K+ flows out of the cell
43. The shape of action potential curve is ………………of the strength of the above
threshold stimulus.
a) independent
b) dependent
c) proportional
d) related
44. Epilepsy and accidental brain damage are diagnosed by………………
a) electrocardiograph
b) electroretinograph
c) electrocephalograph
d) electromyograph
45. Since charges of opposite signs accumulate on the two sides of the axon membrane,
so the axon membrane has ………………
a) capacitance
b) leakage currents
c) axon currents
d) diffusion process
46. The resistance of a length of the axon to a current Iaxon is proportional
to………………
a) membrane capacitance
b) membrane resistance
c) membrane permeability
d) axoplasm resistivity
47. In ………………the amplification and the associated ionic transfers occur only at nodes
of Ranvier.
a) myelinated axon
b) Schwann cells
c) unmyelinated axon
d) cell membrane
48. The action potential is not proportional to the stimulus. Instead, it is:
a) increase as the distance increase
b) depend on the strength of the initial above –threshold stimulus.
c) a transient all—or –nothing response
d) accompanied by dramatic changes of Na+ and K+
49. -An intercontinental submarine cable with periodic amplifiers resembles………………
a) unmyelinated axon
b) myelinated axon
c) dendrites
d) Synapses
50. Equilibrium occur when the potential energy of one ion with charge q , q(Vi – Vo), is
equal to the work necessary to transfer it………………
a) to the region of high concentration
b) to region of lower concentration
c) inside the cell
d) outside the cell
Ch. 26 Particle properties of Light
51. Light incident on the metal plate causes electrons to be emitted. These can travel to
the collector producing ………………
a) photoelectric current
b) X-ray
c) gamma ray
d) AC electric current
52. Einstein suggested that the amount of energy in each light quantum or photon
depends only on the………………
a) frequency of light
b) intensity of light
c) number of light photons
d) speed of light
53. An electron will leave the metal surface under the condition that if it absorbs a light
photon of energy equal to or greater than the,
a) kinetic energy
b) threshold velocity
c) work function
d) metal volume
54. The Bragg condition for X- ray diffraction of any structure is :
a) d sinα = 2mλ
b) 2d sinα = mλ
c) 2d
= mλ sinα
d) 2d / sinα = mλ
55. Laue spots on a screen or film are due to the ………………of wavelets produced by
many atoms.
a) destructive interference
b) constructive interference
c) total internal reflection
d) blackbody radiation
56. ………………has been applied with success to biological molecules, such as proteins
and nucleic acids that can be put into crystalline form.
a) X-ray diffraction
b) Pacemaker
c) Strain gauge
d) Neutron diffraction
57. X-rays are electromagnetic waves with typically a ……………… nm wavelength, are
well suited to study molecular structure.
a) 0.1
b) 5
c) 500
d) 700
58. Light is incident on the surface of a metal for which the work function is 3 eV. If the
frequency of the incident light is 8x1014Hz, what is the maximum kinetic energy of the
electron? (Where h=4.135x10-15 eV s).
a) 6.308 ev
b) 3.308 ev
c) 3.080 ev
d) 0.308 ev
Ch 30 – Ch 31 Nuclear Physics
59. At long time (t=), the capacitor will be fully charged and its potential difference
must equal the EMF . The charge qf is then………………
a) qf= RC
b) qf= 0.37 qo
c) qf= 0.63 qf
d) qf=  C
60. Nuclear species with the same atomic number but different neutron numbers are
called ……………………
a) isotopes.
b) isotones.
c) isobars.
d) isomers.
61. Transmutation of the radioactive elements occurs in ……………………….
a)  decays and  decays.
b)  decays, decays and decays.
c)  decays and decays.
d) Neutron emission and x-ray emission.
62. When a uranium nucleus emits an alpha particle, its atomic number is reduced
by………..
a) one proton.
b) two protons.
c) three protons.
d) four protons.
63. The half life is the time required to decay a radioactive sample to ………… its original
value.
a) one quarter
b) double
c) one fifth
d) one half
64. The absorbed radiation dose for any material depends on the properties of ……..
a) material and beam.
b) material only .
c) radiation beam only.
d) the incident beam angle.
65. The activity (A) of n moles for radioactive sample is related to its half-life (T) and
the number of radioactive nuclei (N) by the relation :
a) 0.693 nTN
b) 0.639 nT/N
c) 0.693 nNA/T
d) 0.639 nN/T
66. ……………….. is the results of instability of the nucleus.
a) Resistivity
b) Radioactivity
c) Continuity
d) Permeability
67. Exposure is defined as the amount of ionization produced in a unit mass of …… at
standard temperature and pressure (STP).
a) water
b) dry air
c) ice
d) uranium
68. The decay constant λ is related to the half life T by………………
a) λ = 0.693 / T
b) λ = 0.693 x T
c) λ = T/ 0.693
d) λ = T + 0.693
69. The biologically equivalent dose in (Sv) is equal to the quality factor times the
………………
a) Activity in (Ci).
b) Exposure in (R).
c) absorbed dose in (Gy).
d) absorbed dose in (rad).
70. The exponential decay formula has the form ………………
a) N = No e-λt
b) N = No / e-λt
c) N = e-λt / No
d) N = No eλt
71. exposure of any material to radiation is depends on the properties of …………………
a) material and beam.
b) material only .
c) the incident beam angle.
d) radiation beam only.
72. If a patient ingests a small quantity of Iodine-131 used in the treatment of thyroid
disorders. Its life-time is 8.1 days. What fraction N/N0 remains after 16.2 days?.
a) 0.25
b) 0.35
c) 0.45
d) 0.50