# Radiation and Matter Revision Questions Radiation and Matter Revision Questions

Multiple Choice and Short Answer

These questions come from an earlier version of the syllabus.

Use g = 10 ms-2.

Some of these questions represent very difficult problem solving.

1. / Two vertical plane mirrors X and Y make an angle of 70o with each other.
If a horizontal ray of light makes an angle of incidence of 40o with mirror X, the angle of reflection at mirror Y is
A / 30o
B / 40o
C / 50o
D / 60o
E / 70o
2. / Three parallel rays of light are incident on a glass block containing an air bubble.
Which diagram shows the path of the rays of light through the block?
3. / An interference minimum (destructive interference) is obtained when the path difference between rays of light from two coherent sources is
A / a whole number of wavelengths
B / an odd number of wavelengths
C / an even number of wavelengths
D / an odd number of half wavelengths
E / an even number of half wavelengths.
4. / The apparatus shown was set up to demonstrate the photoelectric effect.
Which graph shows the relationship between the photoelectric current (I) and the frequency (f) of the radiation?
5. / An important conclusion which resulted from Rutherford’s alpha scattering experiment was that
A / the nucleus of an atom contained only neutrons and protons
B / the mass of the proton was nearly equal to that of a neutron
C / the nucleus of an atom was very much smaller than the atom itself
D / there were large spaces between the atoms in a gold foil
E / alpha particles were helium nuclei.
6. / In the nuclear reaction
the symbol X represents
A / an electron
B / an -particle
C / a photon
D / a proton
E / a neutron.
7. / In the diagram below, a ray of light OP strikes a plane mirror MN at an angle of incidence 40o, and is reflected in a direction PQ.
The mirror is now rotated through an angle of 10o into a new position shown by the broken line, but the direction of the incident light remains unchanged. The angle of reflection will now be
A / 20o
B / 30o
C / 40o
D / 50o
E / 60o
8. / Waves travel from medium A to medium B. In A, their direction is 45oto the normal and in B it is 30o to the normal.
If the velocity of the waves in medium A is 0.283ms-1, the velocity in medium B is
A / 0.200 ms-1
B / 0.231 ms-1
C / 0.347 ms-1
D / 0.400 ms-1
E / 0.425 ms-1
9. / Which of the following gives correct values for the wavelength of visible light in nanometers?
10. / A microwave source produces waves, of wavelength 2.8 cm.
When a metal reflector is placed as shown, an interference pattern is observed with X being on a line of constructive interference.
If OX equals 40cm, then the total path length OYX could be
A / 41.4cm
B / 42.1cm
C / 44.2cm
D / 45.6cm
E / 46.3 cm.
11. / In Young’s double slit experiment, both slits are illuminated by the same light source in order to ensure that the light from the slits is
A / refracted
B / coherent
C / diffracted
D / of equal intensity
E / of equal frequency.
12. / A spectrum of light from a gas discharge tube consists of several distinct coloured lines. This is regarded as evidence that, in the atom,
A / the diameter of the nucleus is very small
B / the nucleus consists of protons and neutrons
C / most of the mass is in the nucleus
D / electrons are the negatively charged particles
E / electrons orbit the nucleus in discrete energy levels.
13. / Figure 1 shows a positively charged gold leaf electroscope with a clean zinc disc on top. Figure 2 shows a similar gold leaf electroscope negatively charged.
Which of the following describes the possible behaviour of the leaves?
14. / Geiger and Marsden under Rutherford’s guidance carried out a series of experiments on the deflection of alpha particles by thin metal foils.
They found that
A / the angles of incidence and reflection were equal
B / refraction occurred, giving sin i /sin r = constant
C / only about one particle in eight thousand was deflected through an angle greater than ninety degrees
D / the alpha particles were absorbed, changing the atomic number of the metal
E / most of the alpha particles were scattered back from the foil.
15. / In the table below, which line correctly describes the nucleus of an atom?
16. / A neutron source is made by mixing the beryllium isotope Be with an alpha-emitting material. The beryllium isotope absorbs alpha-particles and emits neutrons, one for each alpha-particle absorbed. The nuclide remaining after the emission of a neutron is
17. / The table gives the speed of water waves in m 51 for various wavelengths and for four different depths of water.
Which of the following statements can be supported by inspection of the data?
I / For wavelengths of 10—1 m or less, the speed is independent of the depth.
II / At a wavelength of l00 m, the wave speed increases with depth
III / For wavelengths of 1m and more, the wave speeds depend on the wavelength, especially at large depths.
A / I only
B / IIonly
C / I and III only
D / IIand III only
E / I,II and III.
18. / The circuit shown below includes a diode which has negligible forward resistance and infinite reverse resistance.
What is the value of the current in part LM of the circuit when a 8.0 V d.c. supply is connected across XY as indicated?
19. / In this circuit, a cathode ray oscilloscope is connected as shown.
Which diagram shows the trace obtained on the oscilloscope?
(The dotted lines indicate the undeflected beam position on the screen.)
20. / The solar cell and meter shown below are used to measure the irradiance of light from the small lamp, which may be regarded as a point source.
If the meter reading is 4 units when the solar cell is 20cm from the lamp, what adjustment could be made to increase the reading to 64 units?
A / Move the solar cell to the 80cm mark.
B / Move the solar cell to the 40 cm mark.
C / Move the solar cell to the 10cm mark.
D / Move the solar cell to the 5 cm mark.
E / Use a bulb which is four times more powerful.
21. / Which of the following groups of electromagnetic waves is in order of increasing frequency?
A / gamma rays; ultra-violet rays; radio-waves
B / gamma rays; visible light; ultra-violet rays
C / visible light; infra-red radiation; microwaves
D / microwaves; ultra-violet rays; X-rays
E / radio-waves; visible light; infra-red radiation
22. / Light passes from air into a liquid.
Which one of the following represents the refractive index of the liquid relative to air?
23. / Assuming that all frequencies of sound travel through air with the same speed, which one of the following diagrams represents the graph of frequency against wavelength?
24. / Light from a laser shines on two parallel slits ruled on a blackened glass plate. Interference fringes are formed on a white screen behind the two slits.
The separation of the fringes can be increased by
I / increasing the wavelength of the light
II / increasing the distance between the slits and the screen
III / increasing the distance between the slits.
Which of the above statements is/are correct?
A / I only
B / I and II only
C / I and III only
D / IIand III only
E / I, II and III
25. / A white light source is viewed through a diffraction grating. Which of the following would be true?
I / Spectra would be produced on both sides of the central position.
II / There would be a white central image of the source.
III / Blue light would be deviated more than red.
A / I only
B / IIonly
C / I and II only
D / IIand III only
E / I,II and III
26. / When the spectrum of sunlight is observed, there are two dark lines at wavelengths corresponding to 589.0 x 10-9m and 589.6 x 10-9m. These are known to be the wavelengths of the two yellow lines seen in the spectrum of hot sodium vapour.
The dark lines are present because
A / sodium atoms are absorbing energy in the outer layers of the sun
B / sodium atoms are emitting energy in the outer layers of the earth’s atmosphere
C / no sodium atoms exist in the outer layers of the sun
D / these wavelengths are not in the visible range
E / these wavelengths are absorbed in the optical instrument used to view the spectrum.
27. / The diagram represents a simple demonstration of the photoelectric effect. A lamp is switched on and directed at a clean zinc plate, which is mounted on a charged electroscope.
Which of the following factors will decide whether the electroscope discharges, or not?
I / The brightness at which the lamp is operating.
II / The wavelength of light used.
III / The type of charge (+ or —) on the plate.
A / IIIonly
B / I and II only
C / II and III only
D / I,IIand III
E / II only
28. / In order to trace the line of a water-pipe buried about half a metre below the surface of a field, an engineer proposes to add a radioactive isotope to the water.
Which of the following isotopes should she choose?
29. / The following equation shows what happens when a deuteron interacts with a triton.
Energy is released in this fusion reaction because
A / the mass of a triton is greater than the mass of a deuteron
B / the mass of a helium nucleus is greater than the mass of a neutron
C / the mass of the deuteron and triton is greater than the mass of the helium nucleus and neutron
D / the mass of the deuteron and triton is less than the mass of the helium nucleus and neutron
E / the mass of the helium nucleus is greatest.
30. / The half-life of a radioactive sample is 8 days. The sample is held in front of a Geiger—Muller counter and gives a count, corrected for background, of 120 per minute.
A second, corrected count of 120 is taken 24 days later. How many minutes would this second count have lasted?
31. / When light undergoes a change in direction as it travels from one medium into another, the ratio sin1 : sin 2 is a constant, where 1 and 2 are angles related to the direction of the light.
Which of the following diagrams shows both the apparatus required and the angles which should be measured to confirm the above relationship?
32. / In water, sound waves travel 4.5 times faster than they do in air. Sound waves from an undersea earthquake strike the surface of the water at 45oto the normal.
What will happen to the sound waves?
A / They will emerge at 9o to the normal.
B / They will emerge at 45o to the normal.
C / They will emerge at 81o to the normal.
D / They will emerge at 90o to the normal.
E / They will be totally internally reflected at 45o to the normal.
33. / Light of frequency 5 x 1014 Hz passes from air into glass of refractive index 1.5. The speed of light in air is 3 x 108ms-1.
What is the wavelength of this light in the glass?
A / 4 x 10-7 m
B / 6 x 10-7 m
C / 9 x 10-7 m
D / 1 x 1023 m
E / 1.5 x 1023 m
34. / When an ultra-violet lamp is held above a charged electroscope, which has a clean zinc plate fitted as its cap, the leaf drops gradually towards zero.
Which of the following correctly describes the effects of moving the lamp closer to the cap of the electroscope?
35. / Which one of the following graphs correctly shows the relationship between the wavelength and the energy E of photons of electromagnetic radiation?
36. / In a famous experiment performed by Geiger and Marsden in 1908, alpha particles were fired at a very thin gold foil, as shown below.
What could happen to the alpha particles after reaching the foil?
I / They could pass through undeflected like P.
II / They could pass through deflected like Q.
III / They could bounce back like R.
Which of the above statements is/are correct?
A / I only
B / IIonly
C / IIIonly
D / I and II only
E / I, II and III
37. / The diagram represents a series of radioactive changes in which nucleus W forms nucleus X which then forms nucleus Y and finally nucleus Z.
Which one of the following gives the total change of mass number and of nuclear charge?
38. / In the following circuit, the diodes have negligible resistance when connected one way round and infinite resistance when connected the other way round.
What is the current in the circuit at point X?
39. / L1 and L2 are loudspeakers connected to an uncalibrated signal generator. A sound interference pattern is produced.
At P, equidistant from L1 and L2, a microphone registers a maximum. The next maximum is registered at R, where distances L1 R = 4.6 m and L2 R=4.3m.
If the speed of sound in air is 330ms-1, what is the frequency of the note emitted by the loudspeakers?
40. / Which of the following statements about the reflection of light is are true?
I / The reflected ray lies in the same plane as the incident ray and the normal to the reflecting surface, at the point of incidence.
II / The angle between the reflected ray and the normal is equal to the angle between the incident ray and the normal.
III / The reflected ray lies in the same plane as the reflecting surface.
A / I only
B / IIonly
C / I and II only
D / IIand III only
E / I, II and III
41. / Measurements of the intensity of light are taken at a position 1 metre away from a monochromatic point source of light. The measurements are then repeated at a new position which is 2 metres away from the same source. What differences, if any, are observed?
42. / A ray of light is shown in a semi-circular glass block.
Which effect/s occur/s as the angle X is gradually increased to just less than 90o, by moving the ray box in the direction shown?
I / Beyond a certain value of X, no refraction takes place at PQ.
II / At the critical angle, the refracted ray passes along face PQ.
III / There is always a ray reflected from PQ.
A / I and II only
B / IIand III only
C / I and III only
D / I only
E / I, II and III
43. / When light passes from air into glass,
A / the speed of the light increases
B / the speed of the light decreases
C / the frequency of the light increases
D / the frequency of the light decreases
E / the wavelength of the light increases.
44. / S1 and S2are coherent point sources of microwaves of wavelength .
At point X a maximum signal is detected. This could occur when the path difference is
45. / A Young’s double slit apparatus is set up to produce interference fringes on a screen using a monochromatic source of green light.
It would be possible to produce fringes with
greater separation by
A / decreasing the distance between the slits and the screen
B / increasing the distance between the source and the slits
C / increasing the distance between the two slits
D / increasing the width of each slit
E / replacing the light source with a monochromatic source of red light.
46. / In the equation E= hf, what do the three symbols represent?
47. / A line spectrum obtained in an experiment is shown below.
This result leads to a model of the atom. Which of the following assumptions is/are consistent with this model?
I / The electrons in the atom are changing from one energy level to another.
II / The energy levels of the electrons have definite values.
III / The atom is gradually losing electrons.
A / I only
B / IIonly
C / IIIonly
D / I and II only
E / I, II and III
48. / A cleaned zinc plate is placed on the cap of
a gold leaf electroscope which is then chargednegatively.
When ultra-violet radiation is directed towards the zinc plate, the electroscope is discharged.
This is because
A / the ultra-violet radiation ionises the air and the negative ions are repelled by the zinc plate
B / the ultra-violet radiation ionises the air and the positive ions are attracted to the zinc plate
C / the wavelength of the ultra-violet radiation is large enough to eject electrons from the zinc plate
D / the intensity of the ultra-violet radiation is large enough to eject electrons from the zinc plate
E / the energy of each photon of the ultra-violet radiation is large enough to eject an electron from the zinc plate.
49. / Isotope X usually decays by cc-emission into isotope P which then decays by fl-emission to isotope Q.
A small percentage of X decays first by -emission into isotope R which in turn decays by -emission into isotope S.
Which of the following is/are correct?
I / Q and S are identical isotopes.
II / The mass number of X is the same as the mass number of R.
III / The atomic number of X is the same as the atomic number of R.
IV / The atomic number of R is greater than the atomic number of P.
A / I only
B / I, II and IV only
C / I and IV only
D / IIIand IV only
E / IIand III only
50. / Given that the atomic mass of 14N is 23.252 x 10-27kg and that the sum of the atomic masses of 1H and 13C is 23.265 x 10-27kg, it would be reasonable to suppose that the nuclear reaction
A / will result in the emission of energy
B / can only happen if there is a net supply of energy
C / could not take place at all
D / could occur only in conditions of zero gravity, i.e., of “weightlessness”
E / must involve the emission of further atomic particles.
51. / If the refractive index of a certain substance is 1.7, relative to air, what is its critical angle to the nearest degree?
52. / A double-glazed window panel consists of two sheets of glass with an air gap as shown below.
Which diagram shows the path of a ray of light through such a double-glazed panel?
53. / In the arrangements of apparatus shown below, a ray of light is incident on a number of transparent perspex blocks. The refractive index of the perspex is 1.5.
Which arrangement can be used to demonstrate total internal reflection in perspex, without any further adjustment of the apparatus?
54. / The arrangement shown below is used in an experiment to investigate the interference of light. A white light source is used and fringes are seen on the screen.
The colour filter is changed from blue to red and the effect on the fringe pattern is observed. Which of the following statements correctly describes and explains the change in the appearance of the fringes?
A / The fringes would be closer together with RED light because the wavelength of red light is longer.
B / The fringes would be closer together with BLUE light because the wavelength of blue light is longer.
C / The .fringes would be farther apart with RED light because the wavelength of red light is longer.
D / The fringes would be farther apart with BLUE light because the wavelength of blue light is shorter.
E / The fringes would be closer together with RED light because the wavelength of red light is shorter.
55. / Robert sets up an experiment in a darkened laboratory with a small light bulb B1 which emits light at power P.
The light irradiance 50cm from his bulb is 12Wm-2.
Alison repeats Robert’s experiment with a different small bulb B2, which emits light at power 0.5 P.
What is the light irradiance 25 cm from her bulb?
A / 1.5Wm-2.
B / 3.0 Wm-2.
C / 6.0Wm-2.
D / 12.0Wm-2.
E / 24.0Wm-2.
56. / Two loudspeakers are connected to the same signal generator as shown below.
A microphone at X detects maximum intensity. When the microphone is moved slowly upwards, it detects the first minimum at Y.
The wavelength of the sound emitted from the loudspeakers is