IB1 Physics
Version A
November 2001
Time allowed -1 hour
Attempt all questions
1 When a mass oscillates on a spring with small amplitude the period is given very nearly by ............
Which one of the following plots would produce a straight line graph?
2 The volume of rectangular rod is given by (w l h).
The uncertainty in the value of w is 2 % and the uncertainty in l is 0.2 %. The uncertainty in the value of h is 1%. What is the percentage uncertainty in the volume?
a ± 3 %
b ± 6 %
c ± 6.4 %
d ± 3.2 %
3 A car is traveling at constant speed in a straight line on a level road. The diagram that best represents the forces on the car is...
4 In the diagram a wooden block is accelerating down an inclined plane. The weight of the block is W and the normal reaction force between the block and the plane is N. The frictional force acting on the block is F. Angle theta is the maximum angle of the plane before the block begins to slide. The coefficient of static friction between the plane and the block is m.
Which one of the following diagrams best represents the forces on the block?
5 A reel made from an axle and two discs is wound up to the ceiling in a cord wrapped in a single layer around the axle and then released.
Which one of the following graphs best represents the variation of linear speed with time as the discs accelerate towards the floor.
6 A stone is thrown at an angle of 45° above the horizontal.
The time of flight is given by .............. where R is the range on level ground and u is the initial speed.
a ... 2g/u
b ... 2u/g
c ... u/2g
d ... u/2g
7 A mass m has been dragged at constant speed a distance D across a level rough floor, against a friction force given by mN where N is the normal force and m is the coefficient of kinetic friction.
The work done by the dragging force was...
8 A block of mass m is resting on an inclined plane supported by a string as shown.
The string is cut. The block immediately begins to slide.
The direction of the initial movement
is best described by which vector?9 The diagram shows two balls P and Q which are both released at the same time with the same initial vertical velocity.
In the absence of air resistance the ratio of the maximum heights h(P):h(Q) reached by P and Q will be...
a ... bigger than one
b ... one
c ... less than one
d ... can't tell without being given the velocities in the x direction.
10 A mass is suspended from a steel spring and set into vertical oscillation. As it moves it rubs against a rough vertical wall. It loses kinetic energy due to frictional heating.
The maximum rate of energy loss occurs when...
a ... the acceleration is zero.
b ... the velocity is zero.
c ... the displacement is a maximum.
d ... the rate of energy loss is constant because the friction force is independent of velocity.
11 Two asteroids P and Q of equal mass are in orbit about the Earth.
Which statement is correct?
a P has greater total energy than Q.
b Q has greater total energy than P.
c The have the same total energy because they have the same mass.
d The total energy is not constant because the orbits are not circular.
12 A spring has spring constant k and positive set. The force extension graph is shown.
The elastic potential energy stored in the spring when fully extended is...
13 A block of mass m is resting on a level rough table.
It is accelerated by the weight of a block of mass m hung over a frictionless weightless pulley as shown.
The acceleration of the block on the table is given by...
14 A ball of mass m hits the wall and bounces as shown.
v is the vector velocity before and after impact. The impulse delivered to the wall is .....
a ... + 2 mvx
b ... - 2 mvx
c ... + 2mv
d ... - 2mv
15 The diagram shows a section of triple glazed window. The panes of glass are separated by air gaps which are each as thick as one pane of glass. The room temperature is lower than the outside temperature and the two temperatures are constant.
Which one of the following statements is true?
a There is no energy transfer from the outside to the room.
b The rate of energy transfer across the glass is the same as that across the air gaps.
c The rate of energy transfer across the glass is greater than that across the air gaps.
d The rate of energy transfer across the glass is less than that across the air gaps.
16 The graph shows how the potential energy varies with the separation of molecules in a particular solid.
When the solid is heated...
a ... the solid expands.
b ... the solid contracts.
c ... the solid does not contract or expand because the minimum PE remains at the same separation.
d ... it is not possible to tell without the force separation curve.
17 A metal rod has a coefficient of linear expansion of + 0.002.
If the temperature of the rod is increased by 10 °C it will increase in length by about...
a ... 2 %
b ... 0.2 %
c ... 0.02 %
d ... 0.002 %
18 In a given time interval 2400 J of energy is extracted from a refrigerator cabinet and 4800 J of energy is released to the room.
The coefficient of performance for the refrigerator is...
a ... 1.0
b ... 1.5
c ... 2.0
d ... 4.0
19 When sound travels from warm air to cold air which one of the following happens to the frequency f and velocity v of the sound.
a The frequency f stays the same and v decreases.
b The frequency f decreases and v increases.
c The frequency f stays the same and v increases.
d The frequency f increases and v decreases.
20 Two speakers connected to the same signal generator are placed on each end of a stadium at a sports ground. People sitting at some points in the stadium complain of low sound intensity.
Which one of the following actions on its own will be likely to improve the situation?
a Moving both the speakers a little towards the center.
b Moving just one of the speakers a little towards the center.
c Increasing the amplitude of the sound waves by a small amount.
d None of these.
21 The frequency of the fundamental harmonic produced by an organ pipe that is closed at both ends is 300 Hz.
The frequency of the fundamental when both ends of the pipe are opened is...
a ... 75 Hz
b ... 150 Hz
c ... 300 Hz
d ... 600 Hz
22 One brand of optical fiber has a refractive index gradient across the fiber with the slightly higher refractive index along the center line.
The refractive index gradient is provided to....
a ... strengthen the fiber
b ... prevent light leakage between fibers.
c ... make the fiber more flexible.
d ... increase the optical dispersion coefficient of the fiber.
23 A standing wave on a string fixed at both ends has a one meter wavelength. The wave is made by lateral oscillations at one end with a frequency of 4 Hz.
The speed of transverse waves on the spring is...
a ... 2 m/s
b ... 4 m/s
c ... 8 m/s
d ... 16 m/s
24 A photograph of the string shows it to be straight.
What has happened to the energy of the standing wave?
a Standing waves do not carry energy.
b The energy is all kinetic energy of the moving string.
c The energy is stored in the tension of the string.
d The energy is stored in the molecular vibrations of the string.
25 When setting up an ultrasound distance probe with MacMotion a student finds a menu panel which allows the room temperature to be entered.
This panel has been provided because...
a ... the computer clock runs faster at higher temperatures.
b ... the lengths of objects change with temperature due to linear expansion.
c ... the speed of sound varies with temperature.
d ... ultrasound reflections are clearer at lower temperatures.
26 Two resistors of equal resistance are connected in series to a battery with negligible internal resistance. The current drawn from the battery is 2.0 A.
When the two resistors are connected in series the current drawn from the battery is...
a ... 8.0 A.
b .. 4.0 A.
c ... 2.0 A.
d ... 1.0 A.
27 Which one of the graphs best shows how the electric potential due to a charged solid metal sphere of radius a varies with distance from the center of the sphere.
28 A loop made of conducting material is rotated about a horizontal axis XY. At all times during the rotation the loop is in a region of uniform horizontal magnetic field. At the instant shown the loop is parallel to the field.
At this instant which one of the following about the induced current is true?
a The induced current in the loop is a maximum and the flux linking the loop is a maximum.
b The induced current in the loop is a maximum and the flux linking the loop is zero.
c The induced current in the loop is zero and the flux linking the loop is zero.
d The induced current in the loop is zero and the flux linking the loop is a maximum.
29 In the diagram two wires carry equal currents into the page.
The direction of the combined magnetic field at A is best shown by which arrow?
30 The diagram shows a long solenoid of length L connected to a battery of negligible internal resistance. The magnetic field strength at the center of the solenoid is T.
The solenoid is now reduced to half its original length without altering its diameter or the total number of turns.
The best estimate of the field at the center of the shorter solenoid is now...
a ... T/2.
b ... T.
c ... 2T.
d ... 4T.
31 The primary of an ideal transformer has 10 turns and the secondary has 100 turns. The current in the primary is 2 A and the input power to the primary is 12 W.
Which one of the following statements about the secondary current and the secondary power output is true?
a The secondary current is 20 A and the output power is 1.2 W.
b The secondary current is 0.2 A and the output power is 12 W.
c The secondary current is 0.2 A and the output power is 120 W.
d The secondary current is 20 A and the output power is 12 W.
32 A 120 W light bulb is designed to operate from a 240 V rms alternating current mains supply. The maximum value of the current drawn from the supply will be...
a ... two Amps.
b ... half an Amp.
c ... more than 2 Amps.
d ... less than half an Amp.
33 Two parallel metal plates are connected to a battery. Tiny oil drops are introduced into the space between them. The oil drops all drift upwards, but at different rates.
Which statement is not correct?
a All the oil drops are electrically charged.
b Some oil drops have a positive charge.
c All oil drops all have the same charge.
d The oil drops all have a negative charge.
34 An alpha particle from the decay of Uranium 238 is fired at a thin piece of gold foil so that it is deflected at a small angle as it passes through the gold foil.
Which one of the following statements is true?
a The momentum of the alpha particle remains unchanged.
b The kinetic energy of the alpha particle is reduced as it passes through the foil and is then restored to its original value.
c The kinetic energy if the alpha particle remains constant at all times.
d The speed of the alpha particle is the same at all times.
35 An isotope of Americium has a half life of 20 minutes. A sample of the isotope has an initial activity of 1600 disintegrations per second (Bequerel).
The approximate activity of the sample two hours later will be...
a ... 25 B
b .. 100 B
c ... 400 B
d ... 800 B
36 A sample of radioactive isotope X has twice the initial activity of a sample of the isotope Y. The sample of X contains twice the number of atoms as the sample of Y.
If the half life of X is T then the half life of Y is...
a ... T.
b ... 1.5T.
c ... 2T.
d ... 0.5T.
37 When light is shone on to a metal surface electrons can be ejected.
Which of the following statements is not true?
a ... The effect is not the same for all metals.
b ... Ejected electrons have a maximum energy that is dependent on the intensity of the light.
c ... The effect was first explained by Einstein in the early years of the 20th century.
d ... The energy of ejected electrons depends on the frequency of the light.
38 The chromosphere of the Sun has an effective black body temperature of 20,000 °C.
The radiation emitted from the corona is in the..........
a ... UV region of the electromagnetic spectrum.
b ... X -ray region of the electromagnetic spectrum.
c ... gamma ray region of the electromagnetic spectrum.
d ... microwave region of the electromagnetic spectrum.
39 The safe-lights in photographic dark rooms are red because...
a ... red light is easy on the eyes.
b ... red light has relatively low photon energy.
c ... red light is traditional.
d ... red filters are cheap and easy to get.
40 The diagram shows five of the energy levels of the hydrogen atom.
Which of the following statements is not correct?
a Transitions to the ground state are all in the infra red region of the spectrum.
b Transitions to a particular level form a series of lines called a 'ladder' in early work.
c Transitions from level B to C are in the UV region of the spectrum.
d Transitions from levels A to B are in the visible region of the spectrum.
