PHYSICS EXAM 2ND TERM SS1-3

PHYSICS ss1SENIOR SECONDARY SCHOOL 1SECOND TERM EXAMINATION SECTION A: OBJECTIVES1. Gaps are left in the construction of railway tracks to give room for …………. A. contraction B. evaporation C. expansion D. vaporization2.When hot water is poured in a glass tumbler, it might crack due to the …………  of the inner walls of the tumbler A. even expansion B. uneven expansion C. uneven contraction D. even contraction3. The stopper of a bottle can be removed due to the ………… of the glass A. contraction B. expansion C. evaporation D. none of the above4. The following are advantages of thermal expansion of solids except A. bimetallic thermometer B. fire alarm C. sagging of overhead wire D. fitting of wheels in rims5. If heat is removed from solids they A. contract B. evaporate C. expand D. none of the above6. Which of the following is not an effect of heat? A. expansion B. contraction C. change of state. D.  increase in weight 7. Temperature can be measured in the following units except A. degree celsius  B. kelvin C. degree Fahrenheit D. centigrade-meter8. When heat is extracted from water it changes from liquid to gas. What is this process called...a) Vaporization b) Extraporlation c) condensation d) Sublimation 9. The process of by which a gas is converted to a solid is called .................10. Fahrenheit is a unit of ....a) Heat b) Temperature c) Joule d) Energy11. The anomalous expansion of water takes place between/at ………………..A. 10C and 40C B. 0°C and 4°C C. 4°C and 25°C D. all temperature12. The SI unit of linear expansivity is ……… A. per Celsius B. per Fahrenheit C. per Kelvin D. per Joules13. If the linear expansivity of a solid is 1.8 X 10 -6 k-1, the area expansivity will be A.0.9 X 10 -6 B. 3.6 X 10 -6 C. 1.8 X 10 -6 D. 5.4 X 10-614 . A metal of length 15.01m is heated until its temperature rises by 600C. If its new length is 15.05, calculate its linear expansivityA. 0.0004/K B. 0.00004/K C. 0.004/K D. 0.04/K15. The increase in volume of 10cm3 of mercury when the temperature rises by 10°C is 0.182cm3. What is the cubic expansivity of mercury A. 0.000182/K B. 0.0000182/K C. 0.000187/K D. 0.000178/K16.Electophorus and capacitor can store charges A. true B. false C. cannot say D. none of the above17. When an ebonite rod is rub with fur, the fur becomes A. positively charge B. negatively charge C. neutral D. none of the above18. The ebonite rod in question above becomes A. positively charge B. negatively charge C. neutral D. none of the above19. Like charges A. attract B. repel C. disappear D. evaporate20. Charges are unusually concentrated at places where the surface is …………. A.  straight B. sharply curved C. oval in shape D. none of the above21. ………  is a device use to detect charge A. Electrophorus B. Capacitor C. Electroscope D. Inductor22. A lighting conductor is used to protect a building from lighting damage. A. true B. false C. cannot say D. none of the above23. ………… is the sensitive part of an electroscope A. The casing B. The cap C. The gold leaf D. The brass rod24. The casing of an electroscope is earthed so as to screen the leaf from outside interference A. positively charge B. negatively charge C. neutral D. none of the above25  Capacitor is a device that …………. charges A. produces B. emits C. store D. none of the above      26. The silver surface of a thermos flask minimizes heat loss by A. conduction B. radiation C. convection D. evaporation27. Is it advisable to wear a dark shirt in the tropical sun? A. yes it is B. No it is not C. Cannot say D. All of the above28. The following are good conductors of heat except A. steel B. aluminum C. copper D. wool29. The thermal conductivity of copper is greater than lead A. true B. false C. cannot say D. none of the above30. A stone floor feels warm to the feet but a rug or a carpet on the same floor feels cold A. true B. false C. cannot say D. none of the above                                        SECTION B: ESSAYINSTRUCTION: Answer 3 questions in all with question 1 compulsory.1. a) Differentiate between heat and temperature.    b)Mention 3 effects of heat.    c) List 3 types of thermometer    d) State 3 advantages of mercury as a thermometric liquid in a thermometer2. a) What is linear expansivity?    b) What is area expansivity?    c) What is volume expansivity?    d) A brass rod is 2m long at a certain temperature. What will be the length for a temperature rise of 100K , if the linear expansivity of brass is 18 x 10-6K-13. a) State the fundamental law of electrostatics.    b) What is electrostatics?    c) State two uses of Gold-leaf electroscope    d) State one use of i) electrophorus ii) capacitor 4. a) State three properties of electric lines of force.    b) State coulomb’s law.    c) State Newton's Law of Gravitation   d) Draw the magnetic fields surrounding and between two bar magnets with two two South poles facing each other.5. a) Define the following terms for heat transfer  i) Conduction b) Convection c) Radiationb) Draw a magnetic field around a bar magnetc) Draw an electric field aroundi) a test positive charge ii) a test negative charge6. a) List 5 of the forms of energy and give one source of each.    b) Explain how current is generated from battery   c) What is lightning   d) What is the purpose of lightning conducted on the roof of a building? PHYSICS ss2SENIOR SECONDARY SCHOOL 2SECOND TERM EXAMINATION SECTION A: OBJECTIVES1. A waterfall is 630m high. What is the change in temperature of a quantity of water that falls from the top to the bottom of the waterfall? [Neglect heat lost to the surroundings, take acceleration due to gravity as 10ms-2 and Specific capacity of water as 4200 JKg-1K-1] (a) 0.150C (b) 1.500C (c) 15.00C (d) 21.00C (e) 150.00C2. An electric heater rated 12V is used to heat 450g of water when a current of 5A was passed through it. What is the final temperature after 30minutes?  [Specific capacity of water = 4200 JKg-1K-1] (a) 57k (b) 20k (c) 57k (d) 80k (e) 40kIf 60g of water at 90°C is poured into a calorimeter containing 20g of water at 30°C, calculate the final steady temperature of the mixture (a) 90°C (b) 75°C (c) 68°C (d) 25°C (e) 101°C3. How much heat is required to change 10kg of an object from 20°C to 70°C? [Specific heat capacity of the object is 200JKg-1K-1](a) 1x105J    (b) 1x104J    (c) 40J (d) 105J (e) 40x105J5. Which of the following is not used to determine the heat content of a body? (a) mass of the body (b) volume of the body (c) specific heat capacity of the body (d) temperature of the body (e) all of the above6. An un-graduated thermometer reads 2.0cm and 112.0cm at ice and steam points respectively. Determine the true temperature in Kelvin, when the thermometer reads 5.0cm (a) 303.0K (b) 300.0K (c) 278.0K (d) 30.0K (e) 30.3K7. Clinical thermometer differs from other mercury in glass thermometers because it has I. a constriction II. A wide range III. A short range IV. A narrow bore (a) I and II only (b) I and III only (c) III and IV only (d) I, II and III only (e) I, III and IV only8. A platinum resistance thermometer has a resistance of 4Ω at 00C and 12Ω at 1000C. Assuming that the resistance changes uniformly with temperature, calculate the resistance of the temperature when the temperature is 450C (a) 6.0Ω (b) 6.5Ω (c) 7.6Ω (d) 8.4Ω (e) 16.0Ω9. The purpose of constriction in a clinical thermometer is to (a)prevent the mercury from expanding beyond the bulb (b) prevent the mercury from falling back into the bulb until required (c) enable the mercury to expand slowly (d) serve as the lower limit of the scale to be read (e) none of the above10. Mercury has an advantage over other liquids as thermometric liquid because it (a) has low expansivity (b) has higher conductivity (c) vaporizes easily (d) relatively low freezing point (e) none of the above 11. A phenomenon which is used to describe the process by which a substance changes from solid to gas is called (a) evaporation (b) freezing (c) sublimation (d) melting (e) vaporization12. What effect will reducing the surface pressure of a liquid have on its boiling point? (a) increase its boiling point (b) reduces its boiling point (c) it does not have effect (d) increases its boiling point by 5°C (e) none of the above13. Which of the following statement is true about evaporation (a) evaporation occurs at all temperature except at boiling points (b) evaporation only occurs at boiling point (c) evaporation occurs at all temperature (d) all of the above (e) none of the aboveImpurities change the boiling points of liquid.14.  So, salt added to water will (a) increase its boiling point (b) reduces its boiling point (c) it does not have effect (d) reduces its boiling point by 5°C(e) none of the above16. Which of the following statement is true for an ice if the pressure is lowered? (a) the melting point is increased (b) the boiling point is unchanged (c) the melting point is lowered (d) the melting point is unchanged (e) none of the aboveSECTION B17. Write the effect of impurities and pressure changes on melting, freezing and boilingDescribe an experiment to determine the boiling point of a liquid18. An electromagnetic radiation has a speed of 3×108ms-1 and a frequency of 106Hz, calculate its wavelength (a) 3.3×103m (b) 3.0×102m (c) 3.0×10-2m (d) 3.3×108m (e) 3.3×10-3m19. Which of the following is not a mechanical wave (a) wave propagated in stretched string (b) waves in a closed pipe (c) radio waves (d) water waves (e) sound wavesThe maximum displacement of particles of wave from their equilibrium positions is called (a) wave velocity (b) period (c) amplitude (d) wavelength (e) frequency20. The temperature at which the saturated vapor pressure of a liquid is equal to the atmospheric pressure gives rise to a phenomenon called (a) boiling point (b) melting point (c) evaporation (d) freezing point (e) no answer21. The instrument used to measure relative humidity of an environment is (a) hydrometer (b) hygrometer (c) humid-meter (d) hygroscope (e) none of the above 22. Which of these statements is/are correct? (i) the atmosphere above is cooler than the ones below (ii) for unsaturated vapor, the rate at which the liquid evaporates is greater than the rate at which the liquid condenses (iii) mist is of lesser weather effect than fog (a) all of the above (b) (i) and (ii) only (c) (i) and (iii) only (d) (ii) and (iii) only (e) none of the above23. Which of these is true of saturated vapor pressure? (i) saturated vapor pressure of a liquid increases with temperature (ii) saturated vapor pressure of a liquid does not have contact with the liquid (iii) saturated vapor pressure is in a state of dynamic equilibrium with its own liquid (a) all of the above (b) (i) and (ii) only (c) (i) and (iii) only (d) (ii) and (iii) only (e) none of the above24. The temperature at which the water vapors present in the air just sufficient to saturate it is referred to as (a) relative humidity (b) vaporization (c) dew point (d) condensation point (e) no answer25. he equation PxVyTz = constant is Boyle’s law if (a) x=0, y=0, z=1 (b) x=1, y=0, z=0 (c) x=1, y=1, z=0 (d) x=1, y=1, z=1 (e) x=1, y=1, z=-126. A column of air 10cm long is trapped in a tube at 27°C. What is the length of the volume at 100°C? (a) 12.4cm (b) 13.7cm (c) 18.5cm (d) 37.0cm (e) 100cm27. The volume of certain quantity of gas at 27°C is 1200cm3. Calculate its volume at 127°C if the pressure remains constant.  (a) 300cm3 (b) 400cm3 (c) 1000cm3 (d) 1600cm3 (e) 250cm328. A fixed mass of gas of volume 600cm3 at a temperature of 270C is cooled at constant pressure to a temperature of 00C. What is the change in volume? (a) 54cm3 (b) 273cm3 (c) 300cm3 (d) 546cm3 (e) 600cm3A mass of gas occupies 20cm3 at 50C and 760mmHg pressure. What is its volume at 30°C and 800mmHg pressure? (a) 41.4cm3 (b) 20.7cm3 (c) 50cm3 (d) 0.4cm3 (e) 25cm329. Which of the following abatement is true of virtual image (a) it is formed on the screen (b) it is formed by the intersection of actual rays (c) rays of light do not pass through it (d) all of the above (e) none of the above 30. An object is placed between two plane mirrors inclined at 60° to each other. How many images will the observer see? (a) 6 (b) 5 (c) 4 (d) 3 (e) 231. An object is placed 15cm in front of a concave mirror of focal length 20cm, the image formed is (a) real, inverted and diminished (b) real, inverted and magnified (c) virtual, erect and diminished (d) virtual, erect and magnified (e) virtual, inverted and magnified32. A concave mirror can be used to produce can be used to produce a parallel beam of light if a light bulb is placed (a) between its focus and the pole (b) at its focus (c) at its center of curvature (d) between its focus and the center of curvature (e) none of the above33. When an image is formed in a plane mirror, the image formed will be (a) the same size as the object (b) smaller than the object  (c) laterally inverted (d) always virtual (e) all of the above34. Using the real is positive sign convention determine the sign of the focal length of a convex mirror (a) positive (b) negative (c) neutral (d) none of the above (e) options (a) and (b)35. An object is placed in front of a concave mirror of radius of curvature 12cm. if the height of the real image formed is three times that of the object, calculate the distance of the object from the mirror (a) 24 cm (b) 16 cm (c) 12 cm (d) 8 cm (e) 4 cm36. A magnified erect image four times the size of the object is formed by a concave mirror of focal length 12cm. what is the distance of the image from the pole of the mirror? (a) -36cm (b) -18cm (c) -24cm (d) -3.6cm (e) 24cm36. A boy walks away from a plane mirror at a constant speed of 5.0ms-1 in a direction normal to the surface of the mirror. At what speed does his image move away from him? (a) 5.0ms-1 (b) 2.50ms-1 (c) 3.5.0ms-1 (d) 1.25.0ms-1 (e) 0.00ms-137. The image of an object is located 6cm behind a convex mirror. if its magnification is 0.6, calculate the focal length of the mirror (a) 3.75 cm (b) 6.60 cm (c) 10.00 cm (d) 15.00 cm (e) 20.00 cm.38. Evaporation is a ... phenomenon A. chemical B. Surface C. Internal D. nuclear39........ is a collection of rays. A. focus B. Beam C. Sun D. Moon40. An Image formed by an object at the principal focus is always at... A. Infinity B. Divinity C Simplicity D. Visibility SECTION B: ESSAY INSTRUCTION: Answer 4 questions in all with question 1 compulsory.1. a) What is : i) temperature ii) heatb) Distinguish between temperature and heat in a tabular form.c) Give three advantages of mercury over alcohol as a thermometric liquidd) The pressure at ice point for a constant volume gas is 4.81×104Pa. while that of the steam point is 6.48×104Pa. what temperature will this thermometer indicate at 500C2. a) A 250g of lead at 1700C is dropped into 100g of water at 00C.  If the final steady temperature is 12°C, calculate the specific heat capacity of lead.  (Cw = 4.2 x 103 Jkg-1k-1)b)An  immersion heater supplies heat at the rate of 500Js-1 (i) what is quantity of heat produced in 24 minutes c) Define the following terms : i) latent heat ii) specific latent heat of fusion iii)  specific heat capacity iv)heat capacity 3 a) List 3 of the factors affecting evaporation of a liquid. b) Give one difference between real and a virtual imagec) Give four properties of a thermometric liquidd) The length of mercury thread when it is at 00C, 100C and at an unknown temperature θ is 5mm, and 125mm respectively.  Find the value of θ.4a) i) What is evaporation ii) What is boiling?b) Differentiate between boiling and evaporation in a tabular form.c) Stat two effects of impurities on melting point and boiling point of a pure substance.d) i) Define relative humidity ii) Dew point 5. a)  Define specific latent heat of vaporization     b)  i) Define wave ii) List the types of waves and with two examples for each   c) Elias radio station broadcasts at a frequency of 21MHz. If the speed of light in the air 3×108ms-1, calculate the wavelength of the broadcast.    d)  Define i) stationary wave. ii) progressive wave6.a)State these laws and write its mathematical expressioni) Charles’ law ii) Boyle’s lawb) A vessel is filled with a gas at a temperature 500C and a pressure of 76cmHg. Calculate the final pressure if the volume of the gas is doubled while it is heated to 900Cc) State four of the properties of waves and explain one of them.d) State two uses of : i) plane mirror ii) curved mirror PHYSICS SS3SENIOR SECONDARY SCHOOL 3SECOND TERM EXAMINATION SECTION A: OBJECTIVES 1. 50Hz a.c circuit has a voltage of 220V and a current of 5.0A as its effective value. Determine the peak values of the voltage and its current. (a)311.0V and 1.71A  (b) 331.0V and 7.10A (c)  311.00V and 7.10A(d)7.10V and 311.00A2. Calculate the peak voltage of a mains supply of r.m.s value of 220V. (a)112V  (b) 150V  (c) 222V (d) 311VIn 3. An ac circuit the peak value of the potential difference is 180V. what is the instantaneous  potential differences when the phase angle is 45o. (a)45V (b) 90V (c) 90√2 V  (d)180V4. An ammeter connected to an a.c circuit records 5.5A. What is the peak value of the current? (a) 7.8 (b) 7.1 (c) 3.9 (d) 3.5. When compared, the r.m.s value is ..........  the peak value.(a) greater than(b) same(c) lower than (d) inversely proportional to.6. Which of the following statement is not true of the isotope of an element? They A. Are atoms of the same element B. Have the same chemical properties C. Have the same atomic mass D. Have the same mass number7. Which of the following representation is correct from an atom X with 28 electrons and 30 neutrons? A.  3028X       B   2830X      C 5830X   D. 5828X   E. 302X3.  8. Bohr theory provides evidence for the A structure of the atom   B. positive charge of an electron     C existence of energy level in the atom     D. positive charge on a proton9. Which of the following particles determine the mass of an atom? A. protons and neutrons B. Neutrons only C. protons and electrons D. Neutrons and electrons E.  Protons only 10. Which of the following names is not associated with the models of the atom.    A. Isaac Newton   B. Neils Bohr   C. J.J. Thompson   D. Ernest Rutherford   E. John Dalton of the atom. Illustrate with a diagram.11. nucleus  31H decays, a nucleus of 32H is formed accompanied with the emission of (a) beta particles (b) gamma particle (c) alpha particle (d) x-rays.12. The count rate of radioactive substances diminishes from 600 to 150 in 60 secs. Determine the half life of the substance (a) 15 secs (b) 30 secs (c) 45 secs (d) 60secs.13. A  radioactive substance half life of 20hrs. what fraction of the original radioactive nuclide will remain after 80hrs (a) 1/32    (b) 1/16  (c ) 1/8 (d) 15/16414. A material of mass 1.0X10-3kg undergoes fission process which decreases its mass by 0.02%. calculate the amount energy released in the process [c=3X108m/s]      (A) 1.8X1020J (B) 1.8X1013J (C) 1.8X1011J   (D) 1.8X1010J 15 .In a nuclear reaction the mass defect is 2.0X10-6g. Calculate the energy released, given velocity of light is  3X108m/s. (A) 9.0X1007J (B) 1.8X1008J (C) 1.8X1009J  (D) 9.0X1010J16.Which of the following is called photo electric effect. (a) two electrons are created from a quantum of light (b) metals absorbs quanta of light and then emits electrons (c) a high  energy emits  photon as it is slowed down17. The minimum frequency that can cause photo emission of electrons from metal surface is known as (a) wavelength (b) threshold   frequency (c) frequency of the incident light18. The maximum kinetic of the photo electrons depend on (a) work function (b) frequency (c) intensity of the incident ray5. The minimum energy required to liberate an electron from a metallic surface is (a) ionization energy (b) work function (c) kinetic energy,19 Which of the following are not complimentary variables (a) Energy and time (b) energy and position     (c) Energy and mass  (d) Velocity and position .20. The duality of matter implies that matter? (a) Exist as particle of dual  composition (b) has momentum and energy (c) has both wave and particle property (d) is made up of dual materials 21. According to quantum theory, electromagnetic wave is transmitted in tiny bundles of energy called (a) photons (b) electrons (c) photons (d) protons22. Which of the following scientists proposed the uncertainty principle? (a) De Broglie(b) Heisenberg (c) Newton (d) Lenz24.The uncertainty in the measurement of two complementary variables is ____ h/2π (a) ≥ (b) ≥ (c) ≈ (d) = 25. The number of photoelectrona emitted is dependent on the ... of the radiation. a) frequency b ) intensity y c) threshold frequency d) work function26. The dissipated power in a  ac circuit in a resistor is calculated as the product of current, voltage and ....a) phase factor b) phase angle c) phase d) phase difference27. Resonance in an ac circuit occurs when the current is .... a) maximum b) minimum c) zero d) negative28. The resonance frequency is derived from capicative reactance equals .... a) inductive reactance b) inductive capacitance c) impedance is high d) resistive resistance29. Impedance in an RLC circuit is .... (a) Z= √[R²+(XL-Xc)²]  (b) ) Z= √[R²+(XL)²]   ) (c)Z= √[R²+(Xc)²] (d) ) z= √[R²+(Xc-XL)²]30. The diffraction of electron by crystal proves the .... of electron a) wave b) particle c) uncertainty principle c) reflection d) reflective 31. Light causing photoelectons to be emitted from the surface of a metal proves... nature of ligh a) particle b) dynamic c) unstable d) stable 32. Protection from gamma rays can be effected through the use of ,.. block .a) Iron b) Copper shield c) Lead d) Uranium32. Radioisotopes are used in medicine to cure.....a) cancer b) bleeding disorder c) diabetes d) constipation33. The  maximum current is obtained  in the circuit when the impedance is .... This happens when XL = Xc a) minimum b) maximum c) zero d) increasing 34 . fo  = 1 / 2π √LC  is a ... a) resonance frequency b) fundamental frequency c) harmonic frequency d) overtone35.An a.c  voltage of amplitude 2.0 volts is connected to an RlC series circuit.  If the resistance in the circuit is 5 ohms, and the inductance and capacitance are 3mh and 0.05 uf respectively. Calculate the resonance frequency a) 1.3 Hz b) 13Hz c) 130 Hz c) 0.13Hz36. At what frequency will 20uf capacitor have a reactance of 500 ohms?    (a)   100Hz/π (b)   50/π Hz (c) 150/π Hz (d) 100/π Hz      (e) 30/π Hz      37. The phenomemon of radioactivity was first discovered by (A) Marie  Curie   (B) J.J. Thompson    (C) Henri Becquerel  (D) Nent Bohr (E) Enrico Fermi2. 38. A radioactive substance has a half-life of 3 days. If a mass of 1.55g of this substance is left after decaying for 15days,dertermine the original value of the mass (A) 49.6g (B) 37.2g   (C) 24.8g   (D) 12.4g39. Which of the following is usually used to cause fission in an atomic reactor? (A) alpha particles    (B) beta particles  (C ) electrons  (D) neutrons40. A nuclide  20284Y emits in succession an α-particle and β-particle. The atomic number of the resulting nuclide is (A) 198         (B) 83        (C  ) 82     (D) 80.                                                                        SECTION B: ESSAY INSTRUCTION: Answer 4 questions in all with question one compulsory.1.a) Define X-raysb)) State two for each in relation to X-rays:i)  properties ii) uses iii) c ) State one hazard in to relation to X-raysd) An a.c circuit consist of a resistor 100Ω, an inductor 20H and a capacitor 5.0µF connected in series. If the source has 220Vr.m.s, 50Hz across it, calculate; (i). the impedance, (ii). the current flowing in the circuit.2. a) Define: i) radioactivity ii) half-life (b) Write down the relation between half-life and decay constant (c) In 180 minutes, the activity of a certain radioactive substance falls to one –eight of its original value. Calculate its half-life.d)i) nuclide X emits β-particle to form a daughter nuclide Y. write a nuclear equation to illustrate the charge conservation.(ii) the isotope of a nuclide has a half-life of 5.4X103s.Calculate its decay constant.3. a)Explain the terms nuclear fission and nuclear fusion b) ii) Nuclear reaction is given by the equation 2 1H + 31H --------> 42H  + 10n + energy(i) What type of nuclear reaction is it?(ii) state two componenta in a nuclear reactor used to control chain reactionc) State two peaceful uses of nuclear energyd) State two hazards associated with/non-peaceful use of nuclear energy and radiation 4. a) An electron of charge 1.6X10-19C is accelerated in a vacuum from rest at zero volt towards a plate 40KV. Calculate the kinetic energy of the electronb) An electron jumps from one energy level to another in an atom radiating 9.0x10-19J.     If h = 6.6 x 10 -34Js and C = 3.0 x 108m/s, what is the wavelength, and the frequency of the radiation. c) What is photoelectric emission?d) What is thermionic emission?5. a) List 2 applications of photoelectric emission.    b) What is work function of a metal?    c) hf - hfo =E , what does the following represent?(i) h.  (ii) f     (iii) fo    (iv) hf   (v)hfo    (vi) Ed) i) Calculate the threshold frequency of Lithium metal with work function of 2.3eV   ii) Calculate the frequency of incident radiation with wavelength of 3.3 x10-17m irradiating the Lithium metal above.iii) Calculate the work function of the Lithium metal iv) the energy of the the incident radiation abovev) the kinetic energy of the photoelectons    6. a) State 3 properties of cathode rays    b) List 3 properties of alpha particles   c) State two properties of gamma particles   d) List two phenomena supporting wave-particle duality of light