PHY 102 EOS 2015 Resit.docx

**UNIVERSITY OF CAPE COAST** **COLLEGE OF AGRICULTURAL AND NATURAL SCIENCES** **SCHOOL OF PHYSICAL SCIENCES** **DEPARMENT OF PHYSICS** **RE-SIT EXAMINATION: 2014/2015** **PHY 102: GENERAL PHYSICS II (THEORY)** **ANSWER ALL QUESTIONS** **Choose from the letters A -- D which bears the correct A...

**UNIVERSITY OF CAPE COAST** **COLLEGE OF AGRICULTURAL AND NATURAL SCIENCES** **SCHOOL OF PHYSICAL SCIENCES** **DEPARMENT OF PHYSICS** **RE-SIT EXAMINATION: 2014/2015** **PHY 102: GENERAL PHYSICS II (THEORY)** **ANSWER ALL QUESTIONS** **Choose from the letters A -- D which bears the correct ANSWER** 1. A girl is standing in front of a concave mirror. Consider two rays of light, one from her nose and one from her mouth that are parallel as they are traveling toward the mirror. These rays will come together A. at the center of curvature. B. at the focal point C. at the image point. D. behind the mirror if she is too close to the mirror. 2. Which of the following best describes the image of a concave mirror when the object is at a distance greater than twice the focal point distance from the mirror? A. virtual, upright and magnification greater than one B. virtual, upright and magnification less than one C. real, inverted and magnification less than one D. real, inverted and magnification greater than one 3. The lateral magnification for a flat mirror: A. Is a function of the object distance B. Is 1 C. Is a function of the image distance D. Is a function of the object distance and image distance 4. Which of the following best describes the image formed by a plane mirror? A. Virtual, upright and the same size as object B. Virtual, inverted and enlarged C. Real, inverted and reduced D. Real, upright and the same size as object 5. A convex mirror with a focal length of −20 cm forms an image 15 cm behind the surface. If the object height is 1.2 cm what is the image height? A. 3.0 cm B. 0.75 cm C. 0.94 cm D. 0.30 cm 6. Rays of light traveling parallel to the principal axis of a concave mirror will come together A. at the center of curvature. B. at infinity. C. at the focal point D. at a point half way to the focal point. 7. Use of a parabolic mirror, instead of one made of a circular arc surface, can be used to reduce the occurrence of which of the following effects? A.  chromatic aberration B.  mirages C. spherical aberration D. light scattering 8. A student proposes a liquid level indicator as shown above. When a beam of laser is directed towards the liquid surface, part of it is reflected towards the sensor. What is the angle of reflection of the laser beam? A. 40° B. 50° C. 20° D. 25° 9\. Which of the following phenomena of light results in the formation of mirages? 10\. A transparent liquid of refractive index 1.28 fills a tank to a depth of 1.60 mm. By how much does the bottom of the tank appear raised when viewed from above? A. 0.35 m B. 0.32 m C. 0.80 m D. 1.25 m 11\. The speed of light in ice is 2.29 x 10^8^m/s. What is the index of refraction of ice? A. 1.31 B. 1.49 C. 1.33 D. 1.50 12\. A ray of light is incident on a triangular prism at an angle of 48^0^. If it refracts at minimum deviation, the angle of emergence will be A. 24^o^ B. 42^o^ C. 48^o^ D. 60^o^ 13\. When light travels from air into water A. The velocity decreases B. The frequency increase C. The velocity increases D. The wavelength decreases 14\. A diver shines a flashlight upward from beneath a lake (n = 1.33) at an incident angle of 42.5^o^. At what angle of refraction does the light leave the water? A. 64.0^o^ B. 56.5^o^ C. 30.5^o^ D. 26.0^o^ 15. Convex lens always gives a real image if the object is situated beyond A. Focus ---- --------------------- B. centre of curvature C. optical centre D. radius of curvature 16\. An optical fiber in air will totally internally reflect a light ray if it's angle of incidence is at least 39^0^. What is the minimum angle for total internal reflection if the fiber is placed in water? A. 58.5^0^ B. 51.9^0^ C. 56.8^0^ D. 33.2^0^ A. 8.57 cm B. 5.7 cm C. -60.0 cm D. 7.0 cm 18\. What is the focal length of a plano-convex lens made of glass with index of refraction 1.40 and with the curved surface having a radius of curvature of 20 cm? A. 1.3 cm B. 50.0 cm C. 20.0 cm D. 14.3 cm 19\. The air column in a tube is set into resonance by a vibrating tuning fork. The resultant waves in the air column will be A. progressive and longitudinal 20\. Which of the following instruments would a man in a submerged submarine use to view a boat on the sea? A. Periscope B. Binoculars C. Telescope D. Echo sounder 21\. In a simple microscope, the lens used is A. Cylindrical ---- -------------- B. Biconcave C. plano convex D. Biconvex 22\. The distance between two successive peaks of a sinusoidal wave traveling along a string is 2 m. If the frequency of this wave is 4 Hz, what is the speed of the wave? A. 8 m/s B. 1 m/s C. 4 m/s D. 2 m/s 23\. An ultrasonic wave is sent from a ship towards the bottom of the sea. It is found that the time interval between the sending and receiving of the wave is 1.6 s. What is the depth of the sea, if the velocity of sound in the seawater is 1400 m/s? A. 112 m B. 560 m C. 1400 m D. 1120 m 24\. Which of the following statements is not necessarily true regarding mechanical waves? A. They are formed by some source of disturbance B. They carry energy C. They are sinusoidal in nature D. They require a medium through which to propagate *Use the information below to answer the next two questions.* A sinusoidal wave is described by the wave function *y* = 0.25 sin (0.30*x -* 40*t*) where *x* and *y* are in meters and *t* is in seconds. 25\. Determine for this wave the amplitude and the angular frequency respectively. A. 0.25m and -40Hz B. 0.25m and 40Hz C. 40m and 0.25Hz D. 40Hz and 0.25m 26\. The angular wave number and the wavelength respectively. A. 0.30m^-1^ and 18.94m B. 0.30m^-1^and 20.94m C. 20.94m and 0.30m^-1^ D. 18.94m^-1^and 0.30m 27\. Standing waves are produced by the superposition of two waves with A. The same amplitude, frequency, and direction of propagation. B. The same amplitude and frequency, and opposite propagation directions C. The same amplitude and direction of propagation, but different frequencies. D. The same amplitude, different frequencies, and opposite directions of propagation. 28\. It is possible to break a wine glass by singing very loudly at the right note. This phenomenon is called A. Resonance B. Interference C. Diffraction D. Reflection A. 0.3 Hz B. 3.0 Hz C. 416.5 Hz D. 10 Hz 30\. Which statement is true regarding mechanical and electromagnetic waves? A. Both types of waves require a medium. B. Neither types of waves a medium. C. A mechanical wave requires a medium, but an electromagnetic wave does not. D. The speed of an electromagnetic wave can be affected by a medium, but the speed of a mechanical wave cannot. 31\. Doppler effect is produced if: A. The source is in motion relative to the detector B. The detector is in motion relative to the source C. None of the above D. Both of the above 32\.   Which of the following is an example for mechanical wave? A. Sound wave B. Light Wave C. Infrared Radiation D. Radio Wave 33\. A stretched string between two boundaries is set vibrating in the mode of 5^th^ harmonics. How many *Nodes* are formed between these boundaries if the length of the string is 1m? A. 6 B. 2 C. 5 D. 1 34\. Which of the following physical laws obeys the inverse square law? A. Hooke's law B. Coulomb's law C. Ohm's law D. Newton's first law of motion 35\. A 2m stretched string is set to vibrations in the fundamental mode. What is the wavelength of the wave pattern created in the string? A. 1.5 m B. 1 m C. 4 m D. 1 m 36\. Which of the following is true about closed pipes? I. They produce only odd harmonics II\. They produce only even harmonics III\. They produce both odd and even harmonics A. III B. II C. I D. none of the above 37\. A closed organ pipe 2.5m long is sounded. What is the fundamental frequency if velocity of the sound produced is measured to be 340 m/s? A. 10 Hz B. 340 Hz C. 40 Hz D. 34 Hz 38\. Which of the following is true about open pipes? A. III B. II C. I D. none of the above 39\. In the fundamental mode the air column in the *open pipe* vibrates such that the length *L* of the pipe relates to the wavelength of sound in air as A. λ = 2L *B.* λ = L/2 C. λ = L D. λ = 4*L* 40\. The fundamental wave and first overtones are formed at lengths 0.152 m and 0.468 m respectively when a sounding tuning fork of frequency 500 Hz is placed over a pipe immersed in water. Calculate the end-correction in the pipe. 41\. Rubber rods charged by rubbing with cat fur repel each other. Glass rods charged by rubbing with silk repel each other. A rubber rod and a glass rod charged respectively as above attract each other. A possible explanation is that ---- ------------------------------------------------------------------------------ A. Any two rubber rods charged this way have opposite charges on them. B. Any two glass rods charged this way have opposite charges on them. C. A rubber rod and a glass rod charged this way have opposite charges on them. D. All rubber rods always have an excess of positive charge on them. ---- ------------------------------------------------------------------------------ 42\. If *a* = 3.0 mm, *b* = 4.0 mm, *Q*~1~ = 60 nC, *Q*~2~ = 80 nC, and *q* = 36 nC in the figure, what is the magnitude of the electric force on *q*? ---- ------- A. 3.8 N B. 4.4 N C. 5.0 N D. 5.7 N ---- ------- 43\. What is the equivalent capacitance of the combination shown?  ---- ------- A. 29 µF B. 25 µF C. 40 µF D. 10 µF ---- ------- 44\. At what separation (in metres) will two charges, each of magnitude 6.0μC, exert a force of 1.4N on each other? A. 0.51 B. 2.31 C. 0.48 D. 0.23 45\. Determine the charge stored by *C*~1~ when *C*~1~ = 20 μF, *C*~2~ = 10 μF, *C*~3~ = 30 μF, and *V*~0~ = 18 V. ---- ------------------------------------------ A. 0.37 mC B. 0.40 mC C. 0.32 mC D. 0.24 mC ---- ------------------------------------------ 46\. What is the speed of a proton that has been accelerated from rest through a potential difference of 4.0 kV? ---- ----------------- A. 8.8 x 10^5^ m/s B. 9.8 x 10^5^ m/s C. 1.1 x 10^6^ m/s D. 1.2 x 10^6^ m/s ---- ----------------- *Use the information below to answer the next two questions* A wireless set is rated 100 w, 240 V is operated for 15 hours in a day. 47\. What is the electric energy consumed in 40 days? A. 15 Kwh B. 6 Kwh C. 60 Kwh D. 150 Kwh 48\. What is the cost of electric energy consumed in 40 days at 20p per 1KWh? A. 300 p B. 3000 p C. 12 p D. 120 p 49\. 3.0 Kwh means A. power 3.0 Kw is consumed in a time of 1 hour B. power 3.0 Kwh is consumed in a time of 1 hour C. power 3.0 w is consumed in a time of 1 hour D. power 3.0 wh is consumed in a time of 1 hour 50\. Which of the following is the reason why electrical conductors conduct current. A. zero charge. B. induced charge C. free charge. D. none of the above *Use the information below to answer the next two questions.* If 3.0x10^15^ electrons flow through a section of a wire of diameter 2.00mm in 4.0 s 51\. What is the electric charge that flows through the wire? A. 3.0x10^15^ C B. 4.8x10^-4^ C C. 1.5x10^4^ C D. 4.8x10^15^ C 52\. What is the electric charge that flows through the wire? A. 0.75 KA B. 0.75 PA C. 12 PA D. 0.12 mA 53\. What is the operating resistance of a 100-watt household light bulb if the operating voltage of the household electricity is 120V A. 1400 Ohms B. 144 Ohms C. 1.44 Ohms D. 14.4 Ohms 54\. A resistor with resistance of 20 Ohms is connected to a 12-volt battery. What is the current through the resistor? A. 1.6 A B. 6.0 A C. 0.60 A D. 16 A 55\. Three resistors of 6 Ω each are connected as shown in Figure given below. The equivalent resistance between X~1~ and X~2~ is      A. 12 Ω. B. 4 Ω C. 8 Ω D. 2 Ω **56.** Two resistances R~1~ and R~2~ give combined resistance of 4.5 Ω when in series and 1 Ω when in parallel. The resistances are: A. 3 ohms and 6 ohms B. 1.5 ohms and 3 ohms C. 3 ohms and 9 ohms D. 1.5 ohms and 0.5 ohms.     57\. Which of the following is **NOT** a factor affecting the resistance of a conductor of uniform cross-section. A. Mass B. Cross-sectional area C. Material type D. Temperature **58.** Which method can be used for absolute measurement of resistance? A. Ohm\'s law method B. Wheatstone bridge method C. Raleigh method D. Lortentz method. 59\. If the total resistance in a series circuit doubles, current will............... A. be the same B. be halved C. reduce source voltage D. be doubled 60\. Kirchhoff's voltage law states that: A. the sum of the voltage drops in a series circuit is equal to the total applied voltage B. the algebraic sum of the resistances is equal to the sum of the voltages C. the algebraic sum of the individual currents around a closed loop is zero D. the voltages developed across each element in a series circuit are identical **Fundamental Constants** **Quantity** **Symbol** **Value** ---------------------------------- ------------ ------------------------------- Avogadro's number *N~A~* 6.022 141 99 x 10^23^ mol^-1^ Boltzmann's constant *k* 1.380 6503 x 10^-23^ J/K Electron charge magnitude *e* 1.602 176 462 x 10^-19^ C Permeability of free space *µ~o~* 4π x 10^-7^ T.m/A Permittivity of free space *ε~o~* 8.854 x 10^-12^ C^2^/(N.m^2^) Plank's constant *h* 6.626 x 10^-34^ J.s Mass of electron *m~e~* 9.109 x 10^-31^ J.s Mass of neutron *m~n~* 1.674 x 10^-27^ kg Mass of proton *m~p~* 1.672 x 10^-27^ kg Speed of light in vacuum *c* 2.997 x 10^8^ m/s Universal gravitational constant *G* 6.673 x 10^-11^ N.m^2^/kg^2^ Universal gas constant *R* 8.314 J/(mol.K) Coulomb's constant *k* 8.99 x 10^9^ N.m^2^/C^2^ Electron volt *1 eV* 1.6 x 10^-19^ J