AS & A Level Physics - 9702 Paper 1 2010 Summer Zone 2

The SI unit for potential difference (the volt) is given, in base units, by

A student finds the density of a liquid by measuring its mass and its volume. The following is a summary of his measurements.

mass of empty beaker = (20 $\pm$ 1) g

mass of beaker + liquid = (70 $\pm$ 1) g

volume of liquid = (10.0 $\pm$ 0.6) $\text{cm}^3$

He correctly calculates the density of the liquid as 5.0 g $\text{cm}^{-3}$.

What is the uncertainty in this value?

An ion is accelerated by a series of electrodes in a vacuum. A graph of the power supplied to the ion is plotted against time.

What is represented by the area under the graph between two times?

A vector quantity $V$ is resolved into two perpendicular components $X$ and $Y$. The angle between $V$ and component $X$ is $\theta$.



The angle between component $X$ and the vector $V$ is increased from $0^{\circ}$ to $90^{\circ}$.

How do the magnitudes of $X$ and $Y$ change as the angle $\theta$ is increased in this way?

The product of pressure and volume has the same SI base units as:

A small steel ball falls freely under gravity after being released from rest.

Which graph best represents the variation of the height $h$ of the ball with time $t$? 

The diagram shows a velocity-time graph for a vehicle.

The vehicle, moving at $4.0 \text{ ms}^{-1}$, begins to accelerate at time = 0.

What is the vehicle's acceleration at time = 3.0 s? 

The diagram shows two identical spheres X and Y.

Initially, X moves with speed $v$ directly towards Y. Y is stationary. The spheres collide elastically.

What happens? 

Two equal masses travel towards each other on a frictionless air track at speeds of $60\, \text{cm s}^{-1}$ and $40\, \text{cm s}^{-1}$. They stick together on impact.

What is the speed of the masses after impact?

Forces of 3 N, 4 N and 5 N act at one point on an object. The angles at which the forces act can vary.

What is the value of the minimum resultant force of these forces?

An object, immersed in a liquid in a tank, experiences an upthrust. What is the physical reason for this upthrust?

A brick weighing 20 N rests on an inclined plane. The weight of the brick has a component of 10 N parallel with the plane. The brick also experiences a frictional force of 4 N.

What is the acceleration of the brick down the plane? Assume that the acceleration of free fall $g$ is equal to 10 m s$^{-2}$.

A constant force $F$, acting on a car of mass $m$, moves the car up the slope through a distance $s$ at constant velocity $v$. The angle of the slope to the horizontal is $\alpha$.

Which expression gives the efficiency of the process? 

A force of 1000 N is needed to lift the hook of a crane at a steady velocity. The crane is then used to lift a load of mass 1000 kg at a velocity of 0.50 $m·s^{-1}$.

How much of the power developed by the motor of the crane is used in lifting the hook and the load? Assume that the acceleration of free fall g is equal to 10 $m·s^{-2}$.

When ice melts, it contracts. Which row is correct for ice turning into water? 

Atmospheric pressure at sea level has a value of 100 kPa. The density of sea water is 1020 kg m^-3.

At what depth in the sea would the total pressure be 110 kPa?

A spring is compressed by a force. The graph shows the compressing force $F$ plotted against the length $L$ of the spring

What is the spring constant of this spring? 

In stress-strain experiments on metal wires, the stress axis is often marked in units of $10^8$ Pa and the strain axis is marked as a percentage. This is shown for a particular wire in the diagram

What is the value of the Young modulus for the material of the wire?

The diagram shows a steel wire clamped at one end and tensioned at the other by a weight hung over a pulley.

A vibration generator is attached to the wire near the clamped end. A stationary wave with one loop is produced. The frequency of the vibration generator is $f$.

Which frequency should be used to produce a stationary wave with two loops?

Diagram 1 shows a ripple tank experiment in which plane waves are diffracted through a narrow slit in a metal sheet.

Diagram 2 shows the same tank with a slit of greater width.

In each case, the pattern of the waves incident on the slit and the emergent pattern are shown.

Which action would cause the waves in diagram 1 to be diffracted less and so produce an emergent pattern closer to that shown in diagram 2?

Electromagnetic waves from an unknown source in space were found to be significantly diffracted when passing through gaps of the order of $10^{-5}$ m.

Which type of wave are they most likely to be?

Using monochromatic light, interference fringes are produced on a screen placed a distance $D$ from a pair of slits of separation $a$. The separation of the fringes is $x$.

Both $a$ and $D$ are now doubled.

What is the new fringe separation?

Two oppositely-charged parallel plates are arranged as shown.

An electron is released from rest from the surface of the negatively-charged plate. The electron travels from the negatively-charged plate towards the positively-charged plate. Which graph shows how the force $F$ on the electron varies with its distance $x$ from the negative plate? 

In the diagram, the shaded area represents a uniform electric field directed away from the observer (at right-angles into the plane of the paper).

A horizontal beam of electrons enters the field, travelling from left to right.

In which direction is this beam deflected by the field? 

The diagram shows two points P and Q which lie, 90\(^\circ\) apart, on a circle of radius \(r\). A positive point charge at the centre of the circle creates an electric field of magnitude \(E\) at both P and Q.

Which expression gives the work done in moving a unit positive charge from P to Q? 

Which row describes the circumstances under which forces act on a charged particle in a uniform electric field?
[Table_1]

The resistance of a thermistor depends on its temperature, and the resistance of a light-dependent resistor (LDR) depends on the illumination.

Under which conditions will the resistance of both a thermistor and an LDR be highest?

In terms of energy transfer $W$ and charge $q$, what are the definitions of potential difference (p.d.) and electromotive force (e.m.f.)?
[Table_1]

In each arrangement of resistors, the ammeter has a resistance of $2\,\Omega$. Which arrangement gives the largest reading on the ammeter when the same potential difference is applied between points P and Q?

A source of e.m.f. of 9.0 mV has an internal resistance of 6.0 Ω. It is connected across a galvanometer of resistance 30 Ω. What will be the current in the galvanometer?

The resistors P, Q and R in the circuit have equal resistance.

The battery, of negligible internal resistance, supplies a total power of 12W.
What is the power dissipated by heating in resistor R?

In deriving a formula for the combined resistance of three different resistors in series, Kirchhoff's laws are used. Which physics principle is involved in this derivation?

What is the unit of resistivity?

The grid shows a number of nuclides arranged according to the number of protons and the number of neutrons in each. A nucleus of the nuclide $^8_3\text{Li}$ decays by emitting a $\beta$-particle. What is the resulting nuclide?

The following represents a sequence of radioactive decays involving two $\alpha$-particles and one $\beta$-particle.
$^{217}_{85}\text{At} \rightarrow \alpha \rightarrow \nu \rightarrow \alpha \rightarrow \text{W} \rightarrow \beta \rightarrow \text{X}$
What is the nuclide X?

What are the correct descriptions of a $\gamma$-ray and a $\beta$-particle? [Table_1]

What is not conserved in nuclear processes?