1.Which of the following statements for Kıc is incorrect?
a) It depends on specimen thickness.
b) In this condition, specimen thickness is much greater than the crack dimensions
c) Kıc is valid in case of plain strain condition
d) Kıc values are relatively large for ductile materials.
e) The magnitude of Kıc diminishes with increasing strain rate.

2. Which of the following statements is correct?
a) A current produced by the net movements of charged ions is called the metallic conduction.
b) The electrical resistivity is directly proportional to specimen geometry.
c) The electrical resistivity for the material is a function of temperature.
d) The energy in the highest filled state at 0°C is called the Fermi energy.
e) All of the above is incorrect.

3. Which kind of conductivity occurs when a bismuth (Bi) atom is added as a substitutional impurity
to germanium (Ge)?
a) Intrinsic semiconductivity
b) n-type intrinsic semiconductivity
c) n-type extrinsic semiconductivity
d) p-type intrinsic semiconductivity
e) p-type extrinsic semiconductivity

4. Which of the following statements is correct?
a) The carrier concentrations increase with temperature for intrinsic and extrinsic semiconductors
b) The magnitude of hole mobility is always greater compared to the electron mobilities.
c) When a high-purity germanium is added 1023 m-3 antimony atoms, antimony will act as an
acceptor in silicon.
d) The hole effect experiment is carried out in order to determine majority charge carrier type,
concentration, and mobility of some material.
e) All of the above is incorrect.

5. Calculate the density of silver at 420°C, given that its room-temperature (25°C) density is 10.49
g/cm3. Assume that the volume coefficient of thermal expansion, αv, is equal to 2αl.
a) 10.49 g/cm3
b) 10.25 g/cm3
c) 10.54 g/cm3
d) 10.33 g/cm3
e) 10.39 g/cm3

6. I) The thermal conductivity of a plain carbon steel is smaller than for a stainless steel.
II) A single quantum of vibrational energy is called a photon.
III) Metals are typically better thermal conductors than are ceramic materials.
IV) Thermal conductivities are higher for crystalline than noncrystalline ceramics.
Which of the above statement(s) are correct?
a) I, III, IV
b) All of them
c) I, II, III
d) III, IV
e) II, III, IV

8. I) There is a coupling interaction between magnetic moments of adjacent atoms/cations for both
material types.
II) Both ferromagnets and ferrimagnets form domains.
III) Saturation magnetizations are higher for ferrimagnetic materials.
IV) Magnetic moment coupling is antiparallel for ferromagnetic materials, and parallel for
ferrimagnetic.
V) Hysteresis B-H behavior is displayed for only ferromagnetic materials, thus permanent
magnetization are possible for ferromagnets.
For ferromagnetic and ferromagnetic materials, which of the above statement(s) are correct?
a) I, II
b) III, IV
c) I, II, III, IV
d) II, III, IV, V
e) I, II, V

9. The nonreflected light fraction which is transmitted through a 125 mm thickness of glass is 0.89.
So, what is the absorption coefficient of this material?
a) 4.12x10-4 mm-1
b) 9.32x10-4 mm-1
c) 1.61x10-4 mm-1
d) 5.82x10-4 mm-1
e) 1.01x10-4 mm-1

10. Indicate whether the following statements are true (T) or false (F)
I) ……The characteristic color of a metal is determined by the distribution of wavelengths of the
absorbed light radiation.
II) ……The characteristic color of a transparent nonmetal is determined by the distribution of
wavelengths of the nonabsorbed light radiation that is reflected from the material.
III) ……Phonons are elastic waves existing within solid materials.
IV)…… The elemental semiconductor germanium is transparent and colorless to visible light.

11. What effect does temperature rise have on semiconductors, why is it different from conductors?
Explain in detail.

12. The quantum mechanics states that there is not any interaction between an accelerating electron
and atoms in a perfect crystal. So all of the free electrons should accelerate as long as the electric
field is applied, which would cause an electric current that is continuously increasing with time.
But as you know, a current reaches a constant value. Explain why.

One of the explanations for the accident with TWA 800 (exploded in midair after takeoff from JFK airport in New York) was as follows: wire cuts in the vicinity of the central fuel tank caused arcing to occur which ignited the fuel vapor present in the fuel tank. What safety assessment process deals with this kind of failures? Explain your answer.

Outside the nucleus, the neutron itself is radioactive and decays into a proton, an electron, and an antineutrino. The half-life of a neutron (mass = 1.675 × 10-27 kg) outside the nucleus is 10.4 min. On average, over what distance x would a beam of 5.55-eV neutrons travel before the number of neutrons decreased to 75.0% of its initial value? Ignore relativistic effects.

The figure below shows a stream of water in steady flow from a kitchen faucet. At the faucet, the diameter of the stream is 0.960 cm. The stream fills a 125-cm³ container in 16.0 s. Find the diameter of the stream 13.0 cm below the opening of the faucet.

How long does it take electrons to get from the car battery to the starting motor? Assume the current is 149 A and the electrons travel through copper wire with cross sectional area 36.3 mm2 and length 82 cm . The mass density of copper is 8960 kg/m3 and the molar mass is 63.5 g/mol . Avogadro’s number is 6.022 × 1023 . Assume that each copper atom contributes one conduction electron. Answer in units of min.

Interactive LearningWare 22.2 reviews the fundamental approach in problems such as this. A constant magnetic field passes through a single rectangular loop whose dimensions are 0.29 m x 0.61 m. The magnetic field has a magnitude of 1.7 T and is inclined at an angle of 72o with respect to the normal to the plane of the loop. (a) If the magnetic field decreases to zero in a time of 0.61 s, what is the magnitude of the average emf induced in the loop? (b) If the magnetic field remains constant at its initial value of 1.7 T, what is the magnitude of the rate A/ t at which the area should change so that the average emf has the same magnitude?

A tank holds a 1.44-m thick layer of oil that floats on a 0.96-m thick layer of brine. Both liquids are clear and do not intermix. Point O is at the bottom of the tank, on a vertical axis. The indices of refraction of the oil and the brine are 1.40 and 1.52, respectively. A ray originating at O crosses the brine-oil interface at a point 0.5 m from the axis. The ray continues and emerges into the air above the oil. What is the angle that the ray in the air makes with the vertical?

The answer is 44.6. I need an explanation as to why this is the answer. Thanks!

We can calculate the mass of a galaxy by observing how fast stars are moving around its edge. Further we can estimate how many stars are in that galaxy using an average star mass of around 1/2 solar mass. NGC 253 (image below) is a flat spiral galaxy with a diameter of about 60,000 ly. If a star on the edge of NGC 253 is observed to have an angular velocity of about 7.8x10-16 rad/s, (a) calculate the mass of the galaxy and (b) estimate the number of stars in it.

some people describe Newton's second law as a quantitative version of Newton's first law . Describe how this makes sense.

There are two discs of masses 3.0 kg and 2.0 kg and radii 10 cm and 5 cm, respectively. The discs are rotating about their respective center of masses with angular speeds 200 rpm and 300 rpm. The discs are brought together into contact face-to-face with their axes of rotation coincident. a) What is the angular speed of the two-disc system? b) What are the kinetic energies of the discs when they were apart? Denote them as K1 and K2. c) What is the kinetic energy of the two-disc system? Denote it as K. d) Compute difference in kinetic energies |K – (K1+K2)|. How do you account for this difference in kinetic energy?

Bob has just finished climbing a sheer cliff above a beach, and wants to figure out how high he climbed. All he has to use, however, is a baseball, a stopwatch, and a friend on the ground below with a long measuring tape. Bob is a pitcher, and knows that the fastest he can throw the ball is about 33.7 m/s. Bob starts the stopwatch as he throws the ball (with no way to measure the ball\'s initial trajectory), and watches carefully. The ball rises and then falls, and after 0.710 seconds the ball is once again level with Bob. Bob can\'t see well enough to time when the ball hits the ground. Bob\'s friend then measures that the ball landed 127 m from the base of the cliff. How high up is Bob, if the ball started from exactly 2 m above the edge of the cliff?

i) Find the angular separation between the red hydrogen-α spectral line at 656 nm and the yellow sodium line at 589 nm if the two lines are observed in third order with a diffraction grating having 3 500 slits per cm. (Give the answer in degrees, correct to three significant figures.) [6]

            (ii) Using the same diffraction grating as in (i) , what is the highest order that could possibly be observed using violet light of wavelength 420 nm?

In outer space rock 1, with mass 3 kg and velocity < 3500, -2500, 3200 > m/s, struck rock 2, which was at rest. After the collision, rock 1's velocity is < 3000, -1800, 3500 > m/s. What is the final momentum of rock 2?
_2f =  

kg · m/s
Before the collision, what was the kinetic energy of rock 1?
K_1i =  J
Before the collision, what was the kinetic energy of rock 2?
K_2i =  J
After the collision, what is the kinetic energy of rock 1?
K_1f =  J
Suppose the collision was elastic (that is, no change in kinetic energy and therefore no change in thermal or other internal energy of the rocks). In that case, after the collision, what is the kinetic energy of rock 2?
K_2f =  J
On the other hand, suppose that in the collision some of the kinetic energy is converted into thermal energy of the two rocks, where E_thermal,1 + E_thermal,2 = 4.46 ⨯ 10⁶ J. What is the final kinetic energy of rock 2?
K_2f =  J
In this case (some of the kinetic energy being converted to thermal energy), what was the transfer of energy Q (microscopic work) from the surroundings into the two-rock system during the collision? (Remember that Q represents energy transfer due to a temperature difference between a system and its surroundings.)
Q =  J