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WorksheetsWaves & Quantum - OCR AS Phsyics
Total questions: 20
Worksheet time: 1hrs 16mins
The diagram below shows the displacement-time graph of a particle as a progressive wave travels through a medium.
Which point A, B, C, or D has a phase difference of 180° with reference to point X?
A
B
C
D
Which of the following statements is / are true about photons?
1. The speed of a photon changes at the boundary between air and glass.
2. Photons are electrically neutral.
3. The energy of a photon depends only on its wavelength.
1, 2 and 3 are correct
Only 1 and 2 are correct
Only 2 and 3 are correct
Only 1 is correct
A ray of monochromatic light is incident at a boundary between medium 1 and medium 2. The ray is both refracted and reflected at the boundary.
Which of the following statements is / are true?
1. The refracted light and incident light have the same wavelength.
2. The speed of light in medium 2 is greater than the speed of light in medium 1.
3. The angle θ is the critical angle.
1, 2 and 3
Only 1 and 2
Only 1
Only 2
The graph shows the variation of displacement with time for a progressive wave.
Which of the following statements can be deduced from the graph?
The frequency of the wave is 5 Hz.
The graph represents a transverse wave motion.
The amplitude of the wave is 12 mm.
The wavelength of the wave is 60 m.
A ray of light passes through three media with refractive indices n1, n2 and n3. The speed of light in medium 1 is v1, in medium 2 is v2 and in medium 3 is v3. The angle between the ray and the normal in medium 1 is θ1, θ2 in medium 2 and θ3 in medium 3.
Which of the following statements is/are true?
The velocity of light in medium 3 is equal to the velocity of light in medium 1
A. The frequency of light in medium 2 is less than the frequency in medium
In an experiment to measure the wavelength of yellow light from a sodium lamp, a beam of light from a lamp passes through a pair of narrow slits S1 and S2.This produces a pattern of regularly spaced bright and dark lines, called fringes, on a screen as shown in Fig. 5.1.
A student makes the following measurements:
distance S1S2 = 0.8 mm
distance AB on screen = 6.0 mm
distance from slits to screen = 1.6 m
Calculate the wavelength, in nanometre, of the sodium light. (answer in nm)
(a)
Fig. 5.1 shows two loudspeakers S and T connected to a signal generator, emitting sound of a single frequency but with different amplitudes. A person walks in the direction from O to Q. The line OQ is at a distance D from the loudspeakers.
The sound waves emitted individually by S and T have displacements xS and xT at the point P. Fig. 5.2 shows the variation with time t of each of these displacements. Note that the amplitude of the wave from T is twice that of the wave from S.
Calculate the wavelength λ of the sound waves emitted from the loudspeakers. The speed of sound in air = 340 m s−1 in meters. (value only no units needed).
(a)
Fig. 5.1 shows two loudspeakers S and T connected to a signal generator, emitting sound of a single frequency but with different amplitudes. A person walks in the direction from O to Q. The line OQ is at a distance D from the loudspeakers.
Maximum intensity of sound is heard at point O. The loudspeakers are 0.40 m apart and the distance OP is 2.4 m. P is the position of the first minimum.
Calculate the distance D from the loudspeakers to the line OQ in m. (2 sig fig, no units needed)
Assume that the equation used for the interference of light from a double-slit also applies for the sound from these two loudspeakers.
(a)
A guitar manufacturer wants to investigate the quality of sound produced from a new uniform polymer string. Fig. 18.1 shows the string which is kept in tension between a clamp and a pulley. The frequency of the mechanical oscillator close to one end is varied so that a stationary wave is set up on the string.
The frequency of the oscillator is 60 Hz.
Use Fig. 18.1 to calculate the speed of the transverse waves on the string in m s-1. (2 sig fig, no unit needed)
(a)
A guitar manufacturer wants to investigate the quality of sound produced from a new uniform polymer string. Fig. 18.1 shows the string which is kept in tension between a clamp and a pulley. The frequency of the mechanical oscillator close to one end is varied so that a stationary wave is set up on the string.
The frequency of the oscillator is 60 Hz.
The speed v of the transverse waves on the string is directly proportional to √T, where T is the tension in the string.
The tension T in the string is increased by 14 %. The frequency f of the oscillator is adjusted to get the same stationary wave pattern as Fig. 18.1.
Calculate the percentage increase in the frequency f. (2 sig fig)
(a)
Fig. 5.1 shows a long plastic tube immersed in a deep tank of water. A loudspeaker emitting a sound of constant frequency 512 Hz is fixed to the end of the tube. The tube is raised out of the water until a loud sound is first heard, position P. The tube is raised again until a loud sound is heard for a second time, position Q. The distance that the tube is raised between the two positions of loud sound is shown in the diagram.
How many Nodes would form in the longer tube?
1
2
3
4
5
Fig. 5.1 shows a long plastic tube immersed in a deep tank of water. A loudspeaker emitting a sound of constant frequency 512 Hz is fixed to the end of the tube. The tube is raised out of the water until a loud sound is first heard, position P. The tube is raised again until a loud sound is heard for a second time, position Q. The distance that the tube is raised between the two positions of loud sound is shown in the diagram.
Calculate the speed v of sound in the tube in m s-1. (2 sig fig, no unit)
(a)
The length of the tube is 66 cm. The tube is removed completely from the water with the loudspeaker continuing to emit the same frequency of 512 Hz. A loud sound is again heard.
What forms at the top and bottom ends of the tube if it is a harmonic frequency?
Top = node, bottom = anti-node
Top = anti-node, bottom = anti-node
Top = anti-node, bottom = node
Top = node, bottom = node
The length of the tube is 66 cm. The tube is removed completely from the water with the loudspeaker continuing to emit the same frequency of 512 Hz. A loud sound is heard at this frequency.
State the fundamental frequency f0 of the stationary wave in the open tube.
Use the speed of sound is 338 m s-1
(a)
A sodium lamp is rated at 40 W.
12% of the power is emitted as yellow light of wavelength 5.9 x 10−7 m.
How many photons of yellow light are emitted per second from this lamp?
1.4 × 1019
1.2 × 1020
3.6 × 1027
1.0 × 1040
Fig. 4.1 shows the I-V characteristic of a blue light-emitting diode (LED).
The energy of each photon emitted by the LED comes from an electron passing through the LED. The energy of each blue photon emitted by the LED is 4.1 × 10−19 J.
Calculate the energy of a blue photon in electron volts.
(2 sig fig, no unit needed)
(a)
Fig. 4.1 shows the I-V characteristic of a blue light-emitting diode (LED).
The energy of each photon emitted by the LED comes from an electron passing through the LED. The energy of each blue photon emitted by the LED is 4.1 × 10−19 J.
How does the Energy of the blue photon relate to the graph in Fig 4.1
It's from the gradient.
It's from the y-intercept.
it's from the x-intercept.
it's from the area under the line.
Fig. 4.1 shows the I-V characteristic of a blue light-emitting diode (LED).
The energy of each photon emitted by the LED comes from an electron passing through the LED. The energy of each blue photon emitted by the LED is 4.1 × 10−19 J.
Calculate for a current of 20 mA the number n of electrons passing through the LED per second.
(2 sig fig in standard form (1.0 x 1010 or 1.0x10^10, no unit needed)
(a)
Fig. 4.1 shows the I-V characteristic of a blue light-emitting diode (LED).
The energy of each photon emitted by the LED comes from an electron passing through the LED. The energy of each blue photon emitted by the LED is 4.1 × 10−19 J.
Calculate for a current of 20 mA the total energy of the light emitted per second in J.
(2 sig fig, no unit needed)
(a)
Fig. 4.1 shows the I-V characteristic of a blue light-emitting diode (LED).
The energy of each photon emitted by the LED comes from an electron passing through the LED. The energy of each blue photon emitted by the LED is 4.1 × 10−19 J.
Calculate for a current of 20 mA the efficiency of the LED in transforming electrical energy into light energy.
(2 sig fig, no unit needed)
(a)
