Cape Physics

20 12

u

2-

-2JJ[ST OF PHYSICAL CONSTANTS

Speed of light in free space

Permittivity of free

•:

4rc x 10-7 H m· 1

f-lo

Permeability of free wace '

3.00x 108 ms· 1

c

!

spac~

' 8.85 x 10- 12 F m· 1 .:.;

:.: ;. ' Ana ""' ,:. . o·-·. · . ,. ~,..

1.60x 10- 19 C

n·

; r_-. _,._,

.: (fKrti't~ Et/:5~ _

,

i::li:Jt~Jb·~·~:r.r. 2J.f!:i . i.

oj

,

,

,1l·

_;

;ri.·A ~~ ry-.f)~ d:,s ;.:;o~: ~_ - \::nJ~

;::;ji.f~~)kt: t/1 l ,.·h'!i,l

~~')t.E:l"''--·- - ... ~_,-,

nA nN T()

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-31.

Item 4 refers to the following diagram.

When a potential difference of 2 V is applied across a resistor, 10 J of energy are converted to thermal energy. What charge flows through the resistor?

20C

(A) (B) (C) (D)

2.

3.

(A) (B) (C) (D)

.

'

C-ID!

} -

(~)

I

par~bolic toward upper plate

n.:.E

i

1. ( i

I·

;.!' l

' . t.

L1

!. I'

I:, . t

Ii 11

'lh\

:I

,_;~:;! · 1..

.

...

. . ···i "'i ·~ ....

!

:1 i

I I

lI t.

l

Gp ON TO THE NEXT PAGE

-4-

6.

The work done per unit charge in bringing a small positive charge from infinity to a point is the definition of (A) (B) (C) (D)

7.

9.

c,l c,l I T

electric potential potential energy potential gradient electric field strength

What is the electric potential 25 em from a point charge of 6 x 1Q-8 C? (A) (B) (C) (D)

The diagram shows two capacitors of different capacitances, C1 and C2 , connected in parallel to a d. c. source.

Which statement is correct? (A)

0.22 kV 2.2 kV 22.0 kV 220.0 kV

clcz C= C+C 1

(B)

8.

A capacitor of capacitance, C, is made using two parallel metal plates separated by 1 mm in air. The area of overlap of the plates is 20 cm2 • If the distance between the plates is increased to 2 mm and the area of overlap of the plates is halved, what is its new capacitance?

(A) (B) (C) (D)

11.

The effective capacitance

C/4 C/2 2C 4C

(C) (D)

10.

2

The charges on the capacitors are equal. The energy stored by the two capacitors is the same. The potential difference across each capacitor is the same.

Which of the following units is equivalent to the tesla? (A) (B) (C) (D)

NA1 m NC- 1 ms· 1 vm- 1 s NC- 1 m- 1 s

Which of the following diagrams shows the correct direction of the forces on two wires carrying current in opposite directions? (A)

(B)

(C)

(D)

F

t

F

t

I

~-T ·~n. rrnn 1\.n::rYT PAGE/

-5Item 12 refers to the following diagram.

Item 14 refers to the following diagram. Laminated core

12.

A conductor oflength 0.10 misplaced in a magnetic field of9 mT at an angle of 60° to the field direction. It has a current of 2A. Calculate the force on the conductor due to the field. (A) (B) (C) (D)

8 X I0- 4 N 9 X I0- 4 N 1.6 X 10-3 N 1.8 X I0-3 N

14.

The iron core of the transformer in the diagram above is laminated because (A)

(B) (C)

(D)

Item 13 refers to the: following diagram in which conductors P and Q are carrying current into the plane of the paper.

it can be more easily magnitized and demagni tized lamination increases the magnetic flux of the core lamination increases the surface area and the induced e.m.f. in the coils it minimizes the circulation of induced currents in the core

magnetic field to the right

13.

What is the direction of the resultant force on. P when the magnetic field shown is switched on?

(A) (B) (C) (D)

I II III IV

I GO ON TO THE NEXT PAGE

- 6-

15.

The diagrams below show a bar magnet being inserted or withdrawn from a solenoid. In which diagram is the current flow correct? ~Motion

~Motion

sl

(A)

Is

(B) I

I

~Motion

~Motion

sl

(C)

Is

(D)

I

I

16.

A. C. may be represented by the following

In which of the circuits below is the capacitor connected to give a smooth rectified output voltage across the load (R)?

18.

equation, I = I0 sin cot. I0 is (A) (B) (C) (D)

r.m.s. current peak current instantaneous current average current

(A)

a.c. rv supply

R

a. c. rv supplyl

R

Item 17 refers to the following diagram. (B) 100

50 (C)

50

17.

What is the current in the 1OQ resistor? (A) (B) (C) (D)

OA 2A 6A lOA

(D)

~c a. c. rv supplyl

I

GO ON TO THE NEXT PAGE

R

-719.

Which of the following diagrams shows the correct arrangement for a full wave rectifier circuit?

Input

Input

(A)

Input

Input

(C)

20.

(B)

(D)

An example of an INPUT transducer is a (A) (B) (C) (D)

relay buzzer thermistor light-emitting diode

GO ?N TO THE NEXT PAGE

- 8-

Items 21-22 refer to the following diagram which shows an amplifier. 50 !ill

21.

IfVs = -+ 9 V, what is the value ofVout when the input voltage is 1.2 V? (A) (B) (C) (D)

22.

-12 V -9 V 10 v 13 V

The values for the resistors may be changed. Which of the following pairs of values for R 1 and R 2 would give the amplifier the LARGEST bandwidth? Rl

(A) (B) (C) (D)

23.

10kn 20kn 30kn 40kn

~ 100k0 300kn 90kn sokn

An operational amplifier circuit has a gain of 103 and a bandwidth of 103 Hz. What is the approximate bandwidth when the gain is reduced to 10? (A)

(B) (C) (D)

10 Hz 103 Hz 105 Hz 107 Hz

eo

ON TO THE NEXT PAGE

-9Item 24 refers to the following diagram where V 1 and V 2 are input signals.

:>---41.,._---o V out

ov 24.

Wh~t

are the possible values ofR1,

~and~

Rl

~

~

(A)

200kQ

150k.O

600k.O

(B)

200k.O

400k.O

600k.O

(C)

300kQ

400kQ

lOOk.O

(D)

300kQ

400kQ

700kQ

if the output voltage, Vout =

- (3V 1 + 4V 2)?

Item 25 refers to the following diagram.

SOOkQ

Vin=400mV

p 4.0kQ

ro·

o-------------~--------------------------~~--o

25.

From the information given in the operational amplifier circuit above, determine the magnitude of the current through the feedback resistor. (A)

(B) (C) (D)

0.5 ~A 8.0 J-LA 0.1 rnA 8.0 rnA

GO ON TO THE NEXT PAGE 02238010/CAPE 2012

- 10-

Item 26 refers to the following diagrams. 10 k!l 5 k!l

!

Output

Figure 1

voltage

vo

Figure 2

e6.

The sinusoidal alternating voltage shown in Figure 2 is applied to the input of the operational amplifier shown in Figure 1. The voltage of the power supply is± 15 V. Which of the following graphs correctly shows the variation of the output voltage with time?

(B)

(A)

V0 (V)

Vo(V) +6

+15 t(ms)

-15

4

:7

t(ms)

-6 (C)

(D)

GO ON TO THE NEXT PAGE 12238010/CAPE 2012 I

- 1127.

Which of the following shows the correct NOR gate equivalent of the given logic gate? Logic gate (A)

NOT

(B)

OR

(C)

AND

(D)

EX-NOR

Equivalent

Items 28-29 refer to the following diagram which shows a quad-NAND circuit board connected to a 6V supply. It has an indicator diode connected to each output. 6V

ov 28.

If wires are connected as shown, which indicators will be on? (A) (B)

(C) (D)

I and III I and IV II and III II and IV

29.

With inputs I 1 and I2 and output Q, the whole circuit could be replaced by (A) (B)

(C) (D)

an OR gate anAND gate a NOR gate anEXORgate GO ON Tp THE NEXT PAGE

O'J'J~~o1

otr A PP

')til,.,

- 12.. 30.

Two four-bit binary numbers are fed into the inputs X andY of an OR gate. The numbers are represented by the pulse trains in the V-t diagrams below.

V'f' x-~---u ~t

vh....., '

yl

u

u~t

~~z

Which of the following pulse trains represents the output pulse from the OR gate? (A)

Vt

n___ru ___,.,

(B)

v1'

I (C)

(D)

U__,,

v1'

I

I_,.

v1'

n__,.

I

GO ON TO THE NEXT PAGE 02238010/CAPE 2012

- 13-

Item 31 refers to the diagram below which shows a photocell, consisting of an anode A and a cathode, C, inside an evacuated glass tube, connected to an ammeter, voltmeter and a variable d.c. power supply.

uv

~----~v ~----~

A

+ 31.

When the photocell is illuminated with ultraviolet light and photoelectrons are emitted, corresponding current and voltage values are plotted. Which graph correctly shows the relationship between I and V? (A)

(B)

32.

Variable supply

I

(C)

I

I

(D)

Which scientist proposed a quantum theory to explain the photoelectric effect? (A) (B) (C) (D)

Planck Rutherford Einstein Millikan

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02238010/CAPE 2012

- 14-

33.

In an experiment investigating the photo electric emissions from a metal, the stopping potential was found to be 3.0 V when light of frequency 7.5 x 10 14 Hz was used.

36.

(A) (B) (C)

What is the work function of the metal? (A) (B) (C) (D)

5.0 X 10· 19 J 9.8 X I0- 19 J 3.3 X 10-zo J 1.7 X 1Q·20 J

(D)

37. 34.

What is the linear absorption coefficient of a material of thickness 10 em that reduces the incident X-ray intensity to half of its original value? (A) (B) (C) (D)

35.

Which of the following demonstrate the particle nature of electromagnetic radiation?

-0.693 0.693 -6.93 6.93

Interference and polarisation Emission spectra and reflection Photoelectric effect and absorption spectra . ~-decay of nuclei and electron diffraction

Which two scientists conducted an experiment which proves that the nucleus of an atom is very small and positively charged? (A) (B) (C) (D)

Davisson and Germer Moseley and Einstein Michelson and Morley Geiger and Marsden

An experiment to investigate the photoelectric effect was performed and a graph of energy of photoelectrons versus frequency of incident radiation plotted as shown below.

Energy of photoelectrons

/ /

I

/

Frequency (f)

If e is electronic charge, Vs is stopping potential, fis the frequency, m is the mass of an electron and his the Planck constant, then the gradient of the graph is (A) (B) (C) (D)

h elm hmle hie

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.'

- 15Item 38 is about Millikan's oil drop experiment which is depicted in the diagram below.

o--------,------Plates connected to power supply

I

0

0 0

Hole where oil spray enters

0

c:=J::::J Microscope Illuminated oil drops

38.

Which statement about the behaviour of the oil drops during the experiment is correct? (A) (B) (C) (D)

39.

Which of the following statements is true? (A) (B) (C) (D)

40.

When an oil drop is stationary, it must carry a charge. When an oil drop becomes charged, the size of the charge must equal e. When an oil drop moves upwards, only the electric force is acting on it. When no electric field acts, all drops move downwards with the same constant velocity.

The mass of a nucleus is less than the total mass of its separate constituent nucleons. The mass of a nucleus is greater than the total mass of its separate constituent nucleons. The binding energy per nucleon of atoms is a constant as atomic mass is varied. The binding energy per nucleon increases as the atomic mass of the atom increases.

Radioactive lead, ~~ 1Pb decays by two beta particles and one alpha particle. What is the resulting nuclide? (A)

2o3 82

(B)

201 82

(C)

201 84

(D)

Pb Pb Po

211p 84

0

GO ON TO THE NEXT PAGE 02238010/CAPE 2012

- 1641.

When a radioactive nucleus decays an amount of energy, E, is released. At the same time, a small amount of mass, m, is lost. Which of the following gives the amount of energy released? (A)

42.

1 2 E= 2mc

(C)

E=mc

(D)

E=mc 2

45.

The activity of a radioactive source is the

(D)

A freshly made sample of radioactive material gives a count rate of 8000 counts per minute. After twenty days, it gives a count rate of 500 counts per minute. What is the half-life of the material? (A) (B) (C) (D)

1

E=-mc 2

(B)

(A) (B) (C)

43.

44.

intensity of the radiation emitted amount of radioactive atoms number of disintegrations per second number of types of radiation coming from the source

The following statements refer to radioactive decay. I. II. III.

It is a random process. It is a spontaneous process. It is dependent on the chemical

IV.

combination of radioactive elements. It increases with temperature.

4 days 5 days 20 days 80 days

In medicine, radioactive isotopes are often used as tracers to help in locating blockages in the human body. Which of the following isotopes would be MOST suitable for such an application? Isotope

Half-life

(A)

2 minutes

Radiation Emitted Beta

(B)

4 hours

Alpha

(C)

5 hours

Beta

(D)

20 minutes Alpha

Which of the above statements are TRUE? (A) (B) (C) (D)

I and II only II and IV only III and IV only I, II and IV only

ENDOFTEST

IF YOU FINISH BEFORE TIME IS CALLED, CHECK YOUR WORK ON THIS TEST.

02238010/CAPE 2012