ZIMSEC A Level Physics Paper 3 June 2004

Question 101

[2 marks]measurement, uncertainty, projectile-style dynamics

Which is a correct SI base quantity-unit pairing?

ATemperature - joule (J)
BMass - kilogram (kg)
CMass - newton (N)
DCurrent - volt (V)

Question 102

[2 marks]measurement, uncertainty, projectile-style dynamics

Which factor can make a dimensionally correct equation physically wrong?

AMismatched term dimensions
BBad dimensionless constant
CWritten using SI units
DMore than three variables

Question 103

[2 marks]measurement, uncertainty, projectile-style dynamics

Poiseuille's law for fluid flux Φ through a pipe is

\Phi = \frac{\pi}{8}\frac{\rho}{\eta}(P_1-P_2)\frac{R^4}{L}

, where ρ is density, η is viscosity (units Pa s),

P_1-P_2

is a pressure difference, R is the pipe's internal radius and L is its length. Determine the base SI units of Φ.

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Question 104

[3 marks]measurement, uncertainty, projectile-style dynamics

A pipe's length is measured as (2.55 ± 0.01) m and its internal diameter as (20.0 ± 0.2) mm. Using

\Phi \propto R^4/L

, calculate the percentage uncertainty this introduces in the fluid flux Φ.

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Question 105

[2 marks]measurement, uncertainty, projectile-style dynamics

A boy of weight 500 N hangs from the midpoint of a taut rope of total length 40.0 m, stretched between the tops of two tall buildings (negligible sag). The rope snaps just behind him, and he swings on the remaining 20.0 m half of the rope until he hits one wall. Taking g = 9.81 m s^-2, calculate the kinetic energy of the boy on colliding with the wall.

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Question 106

[2 marks]measurement, uncertainty, projectile-style dynamics

The boy in the swinging-rope scenario reaches the wall with kinetic energy 1.00×10^4 J. Given his weight is 500 N and g = 9.81 m s^-2, calculate the speed with which he hits the wall.

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Question 107

[3 marks]measurement, uncertainty, projectile-style dynamics

The boy hits the wall at 19.8 m/s and comes to rest in 0.5 s after his weight (500 N) continues moving horizontally into foam-rubber padding. Taking g = 9.81 m s^-2, calculate the average retarding force on the boy.

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Question 108

[1 marks]measurement, uncertainty, projectile-style dynamics

The boy's fall into foam-rubber padding is brought to rest by a retarding force of about 2020 N, compared to his own weight of 500 N. What does this suggest about the padding's protective ability?

ACannot be assessed here
BLimited, exceeds weight
CProtective within 0.5 s
DFully protective overall

Question 201

[2 marks]gravitation, orbits

State the definition of gravitational field strength g at a point.

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Question 202

[2 marks]gravitation, orbits

State Newton's law of gravitation as an equation for the force F between two point masses M and m separated by a distance r.

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Question 203

[3 marks]gravitation, orbits

Given g = GM_E/R_E^2, calculate the mass of the Earth M_E, taking g = 9.81 m s^-2, the Earth's radius R_E = 6.38×10^6 m and G = 6.67×10^-11 N m^2 kg^-2.

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Question 204

[2 marks]gravitation, orbits

Which equation correctly equates gravitational force and the centripetal force requirement for a satellite (mass m, orbit radius R, angular speed ω) circling Earth (mass M_E)?

AGM_E m/R = mR^2ω^2
BGM_E m/R^2 = mω^2
CGM_E/R^2 = Rω
DGM_E m/R^2 = mRω^2

Question 205

[2 marks]gravitation, orbits

For a satellite of mass m in a circular orbit of radius R about the Earth (mass M_E), gravity supplies the centripetal force:

GM_Em/R^2 = mV^2/R

. Rearrange this to express the satellite's orbital speed squared,

V^2

, in terms of G,

M_E

and R.

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Question 206

[2 marks]gravitation, orbits

If a satellite is moved to a lower circular orbit (smaller R), what happens to its period T?

AT increases
BT stays the same
CT becomes zero
DT decreases

Question 207

[2 marks]gravitation, orbits

If a satellite is moved to a lower circular orbit (smaller R), what happens to its kinetic energy E_K?

AE_K increases
BE_K stays the same
CE_K becomes zero
DE_K decreases

Question 301

[2 marks]refraction, waves

Which pair correctly states the two laws of refraction?

ACoplanar rays; constant sin ratio
BPerpendicular rays; index by angle
CEqual angles; different planes
DCoplanar rays; equal angles

Question 302

[3 marks]refraction, waves

A ray of light in air strikes the top surface of a glass block (refractive index 1.5) at 30° to that surface (so 60° measured from the normal). Calculate the angle of refraction inside the block, measured from the normal.

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Question 303

[2 marks]refraction, waves

What is the critical angle, for a ray travelling from a denser medium toward a less dense one?

ASmallest angle for refraction
BRefraction hits 90 degrees
CAngle where rays run parallel
DFixed at exactly 90 degrees

Question 304

[2 marks]refraction, waves

When does total internal reflection occur at a boundary between a denser and a less dense medium?

ARay hits exactly along normal
BIncidence exceeds critical
CIncidence equals critical angle
DIncidence below critical angle

Question 305

[1 marks]refraction, waves

State what is meant by superposition of waves.

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Question 306

[2 marks]refraction, waves

Explain what is meant by a stationary wave.

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Question 307

[2 marks]refraction, waves

Explain what is meant by a progressive wave.

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Question 308

[3 marks]refraction, waves

Calculate the frequency of red light of wavelength 650 nm, taking the speed of light c = 3×10^8 m/s.

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Question 309

[3 marks]refraction, waves

Why are danger-warning signals (e.g. stop lights) red, even though the human eye is most sensitive to yellow-green light?

ACheapest pigment to manufacture
BRed travels faster than other colors
CLongest wavelength, scatters least
DShortest wavelength, highest energy

Question 401

[1 marks]capacitors

State the definition of capacitance.

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Question 402

[1 marks]capacitors

State the definition of the farad, the SI unit of capacitance.

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Question 403

[2 marks]capacitors

A 47 µF capacitor, initially uncharged, is connected across a 9.0 V d.c. source and charges up. In terms of electron movement, what happens?

AOne plate charges, other loses
BBoth plates gain electrons equally
CElectrons cross the dielectric gap
DPositive charge flows onto plates

Question 404

[2 marks]capacitors

A 47 µF capacitor is fully charged by a 9.0 V d.c. source. Calculate the charge Q stored on it.

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Question 405

[2 marks]capacitors

A 47 µF capacitor stores a charge of 4.2×10^-4 C at 9.0 V. Calculate the energy stored.

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Question 406

[2 marks]capacitors

A charged 47 µF capacitor (holding charge 4.2×10^-4 C) is then connected in parallel with an uncharged 22 µF capacitor, so the total 4.2×10^-4 C of charge redistributes across the combined capacitance of 69 µF. Calculate the resulting potential difference across the capacitors.

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Question 407

[2 marks]capacitors

After redistribution, the 47 µF and 22 µF capacitors (combined capacitance 69 µF) share the original 4.2×10^-4 C of charge at a common potential difference of 6.1 V. Calculate the total energy stored by the two capacitors.

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Question 408

[2 marks]capacitors

The total energy stored (about 1.3×10^-3 J) after the charged 47 µF capacitor shares its charge with an uncharged 22 µF capacitor is less than the 47 µF capacitor's original stored energy (1.9×10^-3 J). Why?

A22 uF capacitor stores negative energy
BEnergy radiated as visible light
CHeat lost during charge redistribution
DCharge is destroyed in the process

Question 409

[2 marks]capacitors

A capacitor and switch are connected in series across a low-voltage a.c. source. Why does the capacitor fail to charge up when the switch is closed?

APolarity reverses each half-cycle
BSwitch blocks all current flow
CBlocked by internal resistance
DThe supply frequency is far too low for current

Question 410

[2 marks]capacitors

Suggest a modification to a circuit where a capacitor and switch are connected in series across a low-voltage a.c. source, so that the capacitor can be charged up using the same source.

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Question 501

[1 marks]pressure, ideal gas, thermal equilibrium

State the definition of density.

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Question 502

[1 marks]pressure, ideal gas, thermal equilibrium

State the definition of pressure.

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Question 503

[2 marks]pressure, ideal gas, thermal equilibrium

A liquid column has height h, cross-sectional area A and density ρ. Write an expression for the weight of this column of liquid, in terms of ρ, A, h and g.

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Question 504

[2 marks]pressure, ideal gas, thermal equilibrium

A U-tube holds paint in one limb and oil in the other, with points A (in the paint) and B (in the oil) at the same height. Will the pressure at A and at B be the same?

ANo, only if the liquids are identical
BYes, but only at the very top
CNo, densities differ so pressure differs
DYes, same level, differing density

Question 505

[3 marks]pressure, ideal gas, thermal equilibrium

A U-tube holds paint in one limb and oil (density 0.897 g/cm^3) in the other. Measured from the common base level, the paint column stands 12.4 cm high and the oil column stands 18.0 cm high. Given that the pressure at the base is the same on both sides, calculate the density of the paint.

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Question 506

[1 marks]pressure, ideal gas, thermal equilibrium

State the ideal gas equation.

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Question 507

[3 marks]pressure, ideal gas, thermal equilibrium

Find the pressure exerted by 6.02×10^23 atoms of hydrogen gas at a temperature of 25.0°C (298 K), placed in a tank of volume 5000 cm^3. Take R = 8.31 J mol^-1 K^-1.

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Question 508

[2 marks]pressure, ideal gas, thermal equilibrium

Explain the meaning of the statement 'two bodies are in thermal equilibrium'.

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Question 509

[2 marks]pressure, ideal gas, thermal equilibrium

Why does heating water from below and cooling it from above (rather than the reverse) save energy?

ASets up convection both ways
BOnly convection from below works
CCooling from below is impossible
DConvection needs no heating at all

Question 601

[1 marks]emf, resistivity, operational amplifiers

State what is meant by electromotive force (e.m.f.).

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Question 602

[1 marks]emf, resistivity, operational amplifiers

State what is meant by internal resistance.

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Question 603

[3 marks]emf, resistivity, operational amplifiers

A heater coil is made from wire of diameter 0.35 mm and resistivity 1.92×10^-7 Ωm. Calculate the resistance per unit length of the wire.

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Question 604

[3 marks]emf, resistivity, operational amplifiers

A heater wire (2.00 Ω/m) is connected to a battery of e.m.f. 36 V and internal resistance 6 Ω. Of the three replacement lengths 1.50 m, 3.00 m and 6.00 m, which length of wire dissipates the greatest power?

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Question 605

[2 marks]emf, resistivity, operational amplifiers

Using the values from the previous calculation, find the power dissipated by the 3.00 m length of heater wire (resistance 6 Ω) when connected to the 36 V, 6 Ω-internal-resistance battery.

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Question 606

[2 marks]emf, resistivity, operational amplifiers

In an inverting-amplifier op-amp circuit (V_in through a 10 kΩ resistor to node Q at the inverting input, a 30 kΩ feedback resistor from the output back to Q, non-inverting input grounded), why is point Q called a 'virtual earth'?

AQ is the circuit's highest voltage
BPhysically wired to earth terminal
CNear 0V via feedback, not earthed
DOp-amp output is grounded there

Question 607

[2 marks]emf, resistivity, operational amplifiers

For the inverting amplifier with input resistor 10 kΩ and feedback resistor 30 kΩ, calculate the gain.

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Question 608

[1 marks]emf, resistivity, operational amplifiers

The inverting amplifier's gain was calculated as -3. Is the feedback in this circuit positive or negative?

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Question 609

[1 marks]emf, resistivity, operational amplifiers

State the effect on the gain of an inverting amplifier when the amount of feedback (the feedback-to-input resistor ratio) is increased.

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Question 610

[1 marks]emf, resistivity, operational amplifiers

State the effect on the bandwidth of an inverting amplifier when the amount of feedback is increased.

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Question 701

[1 marks]photons, photoelectric effect, wave-particle duality

Explain what is meant by a photon.

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Question 702

[2 marks]photons, photoelectric effect, wave-particle duality

Calculate the energy of a photon of wavelength 0.68 µm, taking h = 6.63×10^-34 J s and c = 3×10^8 m/s.

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Question 703

[2 marks]photons, photoelectric effect, wave-particle duality

In an apparatus with a vacuum photocell (illuminated through a quartz window) connected to a microammeter and voltmeter, with a potential divider supplying variable voltage across the electrodes, how would you obtain current readings at different pd values for one fixed light frequency?

AVary the photocell's distance
BVary the light frequency instead
CVary only the light intensity
DVary pd via potential divider

Question 704

[1 marks]photons, photoelectric effect, wave-particle duality

On a current-pd graph for the photoelectric effect at a fixed frequency, the current falls to zero at a particular negative pd value. What is this pd value called?

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Question 705

[2 marks]photons, photoelectric effect, wave-particle duality

What physical quantity does the stopping potential of a photoelectric-effect current-pd graph correspond to?

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Question 706

[2 marks]photons, photoelectric effect, wave-particle duality

Why does the photocurrent level off (saturate) at high positive pd, in a photoelectric-effect current-pd graph?

ASurface becomes fully positive
BMicroammeter reaches its maximum
CAlready collecting all electrons
DLight source runs out of photons

Question 707

[2 marks]photons, photoelectric effect, wave-particle duality

If the light intensity used in a photoelectric-effect experiment is doubled, at the same frequency, what happens to the stopping potential and to the saturation current on the current-pd graph?

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Question 708

[2 marks]photons, photoelectric effect, wave-particle duality

What evidence shows radiation's dual (wave and particle) nature, and how is the apparent contradiction resolved?

AJust particle evidence exists here
BDiffraction disproves wave nature
CWave and particle evidence exist
DJust wave evidence exists here

Physics Paper 3 June 2004

Sit this paper online

The questions

Question 101

Question 102

Question 103

Question 104

Question 105

Question 106

Question 107

Question 108

Question 201

Question 202

Question 203

Question 204

Question 205

Question 206

Question 207

Question 301

Question 302

Question 303

Question 304

Question 305

Question 306

Question 307

Question 308

Question 309

Question 401

Question 402

Question 403

Question 404

Question 405

Question 406

Question 407

Question 408

Question 409

Question 410

Question 501

Question 502

Question 503

Question 504

Question 505

Question 506

Question 507

Question 508

Question 509

Question 601

Question 602

Question 603

Question 604

Question 605

Question 606

Question 607

Question 608

Question 609

Question 610

Question 701

Question 702

Question 703

Question 704

Question 705

Question 706

Question 707

Question 708

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The answers, and why they are the answers

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