ARAB REPUBLIC OF EGYPT
General Secondary Education Certificate Examination 2016
Experimental Egypt Exam (1)
PHYSICS
Time: 3 hours
‫ بالنسبة لألسئلة االختيار من متعدد سيتم تقدير اإلجابة األولى فقط‬:‫تنبيه هام‬
Answer FOUR questions ONLY from the following:
Question One: ( 15 marks)
A. Mention one application of each of the following :
1- Spectrometer
2- Resonant circuit
4-Soft iron core in transformer
5-Resonant cavity in laser
3- Pn junction
B. Firstly: Explain how you demonstrate practically the phenomenon of mutual induction
using two solenoids, DC source and galvanometer- Draw a labeled diagram for the used
electric circuit.
Secondly: Mention one factor that can increase each of the following physical quantity
1- The maximum e.m.f induced in the AC dynamo.
2- The electric resistance of a pure germanium crystal.
3- The Penetrating power of X rays.
C. A coil of inductance 0.06 H connected in series to a capacitor of capacitance 5F and an AC
source of frequency 400 Hz that gives a Voltage of 30V between its terminals. If the ohmic
resistance of the circuit 90 Ω, Find
1- The capacitive reactance of coil and inductive reactance of capacitor.
2- The circuit impedance.
3- The current intensity through the circuit.
4- The phase angle between the total voltage and the current
Question Two: ( 15 marks)
A. What is meant by each of the following ?
12345-
The critical wavelength of a metal 5000 Å.
Current gain in the transistor =99.
The effective value of electric AC current =5A.
The galvanometer sensitivity =20 degree/microampere.
Inductive reactance of a coil =100 Ω
B. Firstly: The opposite table records a
number of
Light
Frequency
radiations with their frequencies and intensities used
color
(Hz)
separately to study the characteristics of photoelectric
Yellow
5.5x1014
Green
6x1014
effect if these radiation falls on metal surface of work
Violet
7.5x1014
function (4.637x 10-19 joule) knowing that (plank's
constant = 6.625 x 10-34 J.s)
1- Which of these rays can liberate electron from the surface of the metal? and why?
Page (1)
Light
intensity
Medium
high
Low
2- Calculate the kinetic energy of the emitted electrons.
Secondly: Three identical resistors are connected as shown to an electric cell
of negligible internal resistance
1- What change in current intensity through the electric cell happens
when the resistor X is replaced by a wire of zero resistance (R = 0).
2- Find the ratio between the readings of ammeter (A) before and after
replacing of resistor X.
C) Four electric resistors 2Ω ,4Ω ,10Ω ,12Ω are connected to a battery of emf 6V and
internal resistance 2Ω it is found that the electric current intensity that flows through
4 Ω resistor double the value of the electric current intensity that flows through 2Ω
1- Show by drawing the way of connecting these resistors together.
2- Calculate the current intensity through the battery.
Question Three :( 15 marks)
A- Choose the correct answer:
1- A transformer has an input DC voltage of 110 volts, 100 turns on the primary and 10 turns on
the secondary. The output voltage is……… (1100 volts - 11 volts - 0 volts)
2- In Compton effect, the gamma ray photon increases in its ……(mass - velocity - wavelength)
3- The possibility of laser to reach far places means it has high …
(intensity – frequency – wavelength.)
4- The ratio between the dimensions of the virus examined by the electron microscope to the
wavelength associating the used electron beam is …….
(Greater than one - equal one - less than one)
5- Sensitive Galvanometer of resistance R is connected to a shunt resistance that decreases its
sensitivity to 1/5. This shunt resistance equals ….
 R R
 R, , 
 5 4
A
transitions A, B , C and D for the electron in the
n=5
n=4
n=3
hydrogen atom. Which of these transitions gives a
n=2
B- Firstly:The opposite figure represents four
spectral line:
n=1
1- of the shortest wavelength.
2- That lies in Panchen's series.
3- The lies in the visible range.
Page (2)
B
C
D
Secondly: Complete the given truth table
C- The coil of an AC dynamo consists of 500 turns each of cross sectional area 100 cm2
revolves at a rate 1500 revolution /minute in a uniform magnetic flux of density 4.2 X 10 3T
22 

 use 
 , Calculate:
7 

1- Maximum e.m.f. induced in the coil.
2- The e.m.f. induced when the coil plane makes an angle 60˚ to the field direction.
3- The e.m.f. after 0.02 seconds from the perpendicular position to the field.
Question Four: (15 marks)
A- Give one of the results based on each of the following.
1- Connection of an inductive coil with a capacitor such that the capacitive reactance equals the
inductive reactance in an AC circuit.
2- Raising the temperature of a silicon crystal (with respect to concentration of charge carriers).
3- Transmission of an atom from the exciting level to another level of lower energy.
4- Inserting an aluminum rod inside an inductive coil through which an AC current passes.
5- Using Molybdenum (atomic number 42) as a target material in Coolidge tube instead of
Tungsten (atomic number 74)
1- Firstly: Prove that:
i) The unit of
is a unit of electric resistance.
ii) The unit of R.C is the unit of
L
R
Where L: self-inductance
R: resistance
C: capacitance
2- What is physical quantity measured by the following units?
J.s Amp.m2
Secondly: Draw a circuit for a transistor as a switch (On condition). Then calculate the value of
the collector current IC when VCC = 1.5 volt and the voltage difference between the collector and the
emitter VCE = 0.5 V and RC = 500 ohm.
B- A solenoid 10cm long and cross sectional area 25cm2 has 400 turns. A current of intensity
4 ampere passes through it. Given that permeability of air (air = 4πx10-7Wb/Amp.m)
Find:
1- The magnetic flux density at an interior point on its axis.
2- Self-inductance of the coil.
3- The average emf induced in the coil when the current is reversed in 0.1 second.
Page (3)
Question Five: (15 marks)
A- Compare between each pair of the following:
1- Effect of increasing frequency and intensity of incident light.
(with respect to number of emitted electrons by photoelectric effect).
2- Electric motor and moving coil galvanometer
(with respect to the direction of current in its coil when connected to a battery).
3- Laser and ordinary light (with respect to monochromatic property).
4- Hot wire ammeter and moving coil galvanometer.(with respect to the idea on which the
operation of each is based) .
4Ω
B- Firstly: Analyze the given circuit in the opposite
diagram using Kirchhoff’s laws to find:
a) VB1 and VB2
b) The voltage drop across e & b
Secondly: Write down the scientific term for each of
the following
1- Numerically equal to the E.M.F induced in a
a
I1 = 1.4 A
VB1
4Ω
b
c
I3 = 0.8 A
VB2
r = 1Ω
r = 1Ω
10Ω
f
d
e
straight wire of length one meter moving perpendicular in a uniform magnetic field at
velocity 1m/s.
2- Emission spectrum as a result of transition of electrons in the atom when their lifetime in the
excited levels is over.
3- The state in which the number of atoms in the excited state exceeds the number of atoms in
the lower state.
C- An inductive coil of resistance 4 ohm is connected to an AC source of frequency (F) Hertz that
can be varied. The inductive reactance (XL) ohm corresponding to each frequency (F) is
calculated by knowing the potential difference and current intensity in the circuit. The
following data are recorded :
F(Hz)
7
14
21
28
35
42
y
XLΩ
4.4
8.8
13.2
17.6
S
16.4
30.8
Plot a graphical representation for the relation between the source frequency (F) on x-axis and
the inductive reactance of the coil (XL ( on the y-axis. From the graph find:
1- value of Y&S
2- The inductance of the coil
3- Capacitance of the capacitor that if were connected in the circuit made it in resonance when
the inductive resistance of the coil was 30.8 Ω.
‫أنتهت األسئلة‬
Page (4)