Question 1

Repeating readings in an experiment reduces:

1. Both random and systematic errors
2. Random errors only
3. Systematic errors only
4. Neither random, nor systematic errors

Question 2

Two masses, X and Y, are 62\pm2 kg and 28\pm1 kg respectively. Which of the following has the largest fractional uncertainty?

1. 2X + Y
2. X – 2Y
3. \frac{3Y}{X}
4. 4XY

Question 3

A biker is traveling on a horizontal road in a straight line. She stops pedalling and allows the bike to come to rest.  

Which free-body diagram correctly represents the forces acting on the biker from the moment she stops pedalling to the moment she comes to rest?

Question 4

A block is sliding down on an inclined plane with constant acceleration a as shown on the diagram.

Which free-body diagram shows the forces acting on the block?

Question 5

A speedboat starts from rest and accelerates at 5.0 m s^{-2}. What is the velocity of the speedboat after it has travelled a distance of 10 m?

1. 2.5 m s^{-1}
2. 5.0 m s^{-1}
3. 10 m s^{-1}
4. 50 m s^{-1}

Question 6

A small object of mass M moves at constant speed v in a vertical circle on a string of length R. Point A is at the top of the circle.

What is the tension in the string at point B?

1. M\left (\frac{v^{2}}{R}-\frac{\sqrt{3}}{2}g\right )
2. M\left (\frac{v^{2}}{R}+\frac{\sqrt{3}}{2}g\right )
3. M\left (\frac{v^{2}}{R}-\frac{1}{2}g\right )
4. M\left (\frac{v^{2}}{R}+\frac{1}{2}g\right )

Question 7

Two spherical objects, X and Y, both of radius R are fired horizontally from a cliff on a planet that has no atmosphere. The objects have the same initial kinetic energy. The mass of X is M and the mass of Y is 2M. 

What is true about the horizontal distance travelled by each object and the time taken for the objects to reach the ground?

Question 8

A dog walks along a horizontal, straight road. The speed of the dog, v, varies with time, t as shown on the graph below.

What is the acceleration of the dog at t = 8 s and what is the distance travelled by the dog during the final four seconds of its motion?

Question 9

A thermally isolated tube contains only water molecules. The tube is cooled to the freezing point of water. While the water is changing phase:

1. its temperature decreases.
2. the mean potential energy of the water molecules decreases.
3. the mean kinetic energy of the water molecules decreases.
4. the mean thermal energy of the water molecules decreases.

Question 10

A balloon and a glass jar both contain particles of the same ideal gas and are connected as shown. The tap connecting the balloon and the glass jar between A and B is closed. The pressure and the temperature in both the balloon and the glass jar are p and T respectively. The initial volume of the balloon is 8V and the volume of the glass jar is 4V.

When the tap is opened, the temperature of the gas particles does not change, while the pressure in both the balloon and the glass jar becomes 2p.

What is the new volume of the balloon?

1. V
2. 2V
3. 4V
4. 16V

Question 11

A container has 36 g of Carbon-12 and 120 g of Magnesium-24 atoms. The total number of atoms in this container is:

1. 4.8 \times 10^{22}
2. 4.8 \times 10^{23}
3. 4.8 \times 10^{24}
4. 4.8 \times 10^{25}

Question 12

A pendulum is oscillating with simple harmonic motion (SHM). Which one of the following four statements is not true about the motion of the pendulum?

1. The direction of its acceleration always points towards the equilibrium position.
2. Its velocity and acceleration have opposite directions for half of the period.
3. Its displacement and acceleration are directly proportional.
4. The restoring force acting on the pendulum and its velocity are directly proportional.

Question 13

Two coherent waves, A and B, are generated at a distance of 1 km and 2 km respectively from a wave detector located at point M. The phase difference between the waves is zero and the wavelength of each wave is 500 m. The intensity due to Wave A at point M is I. The amplitude of wave B is four times the amplitude of wave A.

What is the resultant intensity at M?

1. I
2. 2I
3. 3I
4. 5I

Question 14

The distance between two adjacent nodes on a standing wave is 4 cm. What is the wavelength of the wave?

1. 1 cm
2. 2 cm
3. 4 cm
4. 8 cm

Question 15

Monochromatic green light is incident on a double slit and creates an interference pattern on a screen located at a distance a from the slits. The distance between the slits is d and the fringe spacing of the pattern is b.

What changes in d and the colour of the light will definitely cause the value of b to decrease?

Question 16

A and B are two points along a standing wave. The distance between A and B is 375 m. The wavelength of the wave is 150 m. What is the phase difference between A and B?

1. Zero
2. \frac{\pi}{4}
3. \frac{\pi}{2}
4. \pi

Question 17

A proton is held at rest between two parallel, charged plates. The gravitational force acting on the proton is negligible. 

In which direction will the proton move when released?

1. Left
2. Right
3. Downwards
4. Upwards

Question 18

Two resistors are connected to a cell. The emf of the cell is 20 V and the potential difference across the 4 \Omega resistor is 8 V.

What is the internal resistance of the cell?

1. 2 \Omega
2. 4 \Omega
3. 6 \Omega
4. 8 \Omega

Question 19

Wires X and Y are in the same plane, they are perpendicular and carry equal currents. The direction of the magnetic field due to the currents at point B is as shown on the diagram. 

What is the direction of the electron flow in X and Y?

Question 20

When the potential difference across a wire of length L is V, the power dissipated in the wire is P. When a potential difference of 4V is applied across a second, similar wire, the power dissipated in the second wire is 2P. What is the length of the second wire?

1. 2L
2. 8L
3. 16L
4. 32L

Question 21

Moon A has mass M, radius R and the gravitational field strength on the surface of Moon A is g. Moon B has mass 3M and the gravitational field strength on its surface is \frac{g}{4}.

What is the diameter of Moon B?

1. 2\sqrt{3}R
2. 4\sqrt{3}R
3. 12R
4. 24R

Question 22

A stone of mass M is attached to a string and moves in a horizontal circle or radius R. It takes the stone 2 seconds to complete one revolution.

What is the work done by the centripetal force during 1 second of the stone´s motion?

1. Zero
2. 2\pi^{2}R^{2}M
3. \pi^{3}R^{2}M
4. \pi^{3}R^{2}M

Question 23

The radius of a planet is R. A satellite, which orbits the planet at a distance R above the surface, has acceleration a and orbital period T. The satellite then is moved into an orbit at a distance of 3R from the surface of the planet. 

What should be the new orbital period of the satellite in order for its acceleration to remain a?

1. \sqrt{2}T
2. 2T
3. \sqrt{3}T
4. 3T

Question 24

The diagram shows some of the energy levels of an atom.

How many different wavelengths are there in the absorption spectrum of the atom?

1. 4
2. 5
3. 10
4. 16

Question 25

The existence of atomic energy levels is supported by:

1. evidence from emission and absorption spectra.
2. the Rutherford-Geiger-Mardsen scattering experiment.
3. observations related to the wave nature of light.
4. the neutron-to-proton ratio of stable elements.

Question 26

Nucleus A decays into nucleus B as shown in the equation:

A \rightarrow B + 2\alpha + 4\beta^{-}

Which of the following statements is not true about A and B?

1. B is an isotope of A.
2. The nucleon number of B is smaller than the nucleon number of A.
3. B has the same number of protons as A.
4. B has the same number of neutrons as A.

Question 27

The graph shows how the average binding energy per nucleon, A, varies with the atomic number, Z.

Which of the following statements are correct?

I. The most stable elements are found around the maximum point of the graph.

II. Larger Z means more energy is needed to disassemble the given nucleus

III. Total binding energy is proportional to the atomic number

1. I and II only
2. I and III only
3. II and III only
4. I, II and III

Question 28

The Sun emits 4 \times 10^{26} J of energy per second. Of this, approximately 1400 J is incident on one square meter of the top of the atmosphere. The atmosphere above a forest reflects 400 J of this energy and the rest reaches the forest. The amount of energy absorbed by the forest is 280 J. 

What is the albedo of the forest?

1. 0.20
2. 0.28
3. 0.70
4. 0.72

Question 29

Control rods in a nuclear power plant:

1. reduce the number of neutrons that are available for further fission.
2. convey energy from the reactor to the turbines.
3. slow down neutrons.
4. contain the reactor core.

Question 30

Two photovoltaic panels, A and B, are in the shape of a circle. The radius of A is R and its efficiency is 30%. The radius of B is 2R and its efficiency is 10%. The photovoltaic panels produce the same amount of energy during an hour of sunshine. Panel A is exposed to 6 hours of sunshine per day.

How many hours of sunshine should panel B be exposed to in order for the two panels to produce the same amount of energy per day?

1. 4.5
2. 6
3. 9
4. 10.5