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WorksheetsSemiconductor diode
Total questions: 60
Worksheet time: 29mins
Materials which can conduct electricity better than insulator,but not as well as conductors. This is the definition of
diode
semiconductor
conductor
insulator
superconductor
Which is not one of the properties of semiconductor?
4 electrons in outermost orbit, in covalent bonding.
atoms vibrate causes electron to break free from the bonds.
Electron free leaves hole.
Semiconductor has 2 types of charge carriers.
all of the above are the properties of it
Doping of Semiconductors
materials which can conduct electricity better than insulator, but not as well as conductors.
The process of adding of a certain amount of specific impurities atoms in the pure semiconductor.
when 4 electrons in outermost orbit.
These are the characteristics of pentavalent impurities except
•5 valence electron.
•contributing extra free electrons.
•produce n-type semiconductors.
•produce p-type semiconductors.
These are the characteristics of Trivalent impurities except
•3 valence electrons
•produce p-type semiconductors
•producing a "hole".
Boron, aluminium and gallium are the examples.
Antimony, arsenic, and phosphorus are the examples
which statement is correct? (the dark circles represent the electrons)
p-type of the diode is connected to the negative terminal.
Electron moves across the p-n junction, makes the diode forward biased
current will not flow in the circuit
reverse biased circuit
what is the meaning of rectification?
a process of smoothing using a capacitor
a process of adding impurities to pure materials
a process of converting an alternating current into a direct current by using a diode.
The diagram is a process
of doping
of adding impurities
of half-wave rectification
of full-wave rectification
This is a graph that is seen on CRO. How is it change after full wave rectification process?
Choose the diagrams that show smoothing process has occured
Component that Convert AC to DC and allow current to flow in one Direction
Capacitor
Diode
Inverter
Resistor
Anode is _________ Polarity in diodes
Negative
Positive
Ground
Hot Side
Types of diodes used in lighting system and display
LED
zener diodes
rectifier diodes
schottky
What is the name of this Diode?
PN junction
LED
silicon
PNP
Diode has polarity
anode and cathode
on and off
output and input
none of the above
The region on either side of the junction which becomes free from the mobile charge carriers is called
Energy gap region
Charge free region
Diffusion region
Depletion region
Characteristics of a diode that helps in rectification
Allows Unidirectional flow of current
Allows Bidirectional flow of current
Opposes the flow of current
conducts in reverse biased
During formation of p-n junction
an electron diffuses from n to p side
a hole diffuses from p to n side
a hole diffuses from n to p side
an electron diffuses from p to n side
In the forward bias arrangement of a p-n junction diode,
the n-end is connected to the positive terminal of the battery
the p-end is connected to the positive terminal of the battery
the direction of current is from n-end to p-end in the diode
the p-end is connected to the negative terminal of the battery
The process of adding an impurity to an intrinsic semiconductor is called
Doping
Ionization
Recombination
Atomic modification
Number of diodes a Bridge Rectifier has
1
4
2
3
The characteristics of p-type semiconductors is includes
Majority carriers are holes
Has tendency to gain electron
Has tendency to donor electron
Easy to conduct electricity
The minority carriers in P-type silicon are called _________________
Neutron
Proton
Electron
Hole
These are the characteristics of Trivalent impurities except
•3 valence electrons
•produce p-type semiconductors
•producing a "hole".
Antimony, arsenic, and phosphorus are the examples
How is conduction increased in an p-type semiconductor?
by increased applied electrical field
by decreased applied electrical field
by the availability of extra holes
by the availability of donor electrons
Diagram shows a circuit consisting of a diode and a bulb. When the switch is on, the bulb does not light up. What needs to be done to light up the bulb?
replace the diode with a new one
reverse the connection of the diode
increase the number of bulbs
connect a resistor in series with the bulb
Diagram shows four identical bulbs, P, Q, R and S, and four electronic components connected in a circuit. Which of the following bulbs will light up continuously when the switch is on?
P and Q only
P, Q and R only
R and S only
P, Q and S only
Which of the following graph shows a half-wave rectification with smoothing?
Which of the following rectifier circuit shows full-wave rectification with smoothing?
Which of the following is not correct about capacitor?
Connected in parallel to the load resistor
Produce a smoother and steadier d.c. voltage
Discharged when there is no current flow in the circuit
Lower capacitance will produce smoother d.c. voltage
The forbidden energy gap for Silicon is of the order of
0.7 eV
0.3 eV
1.1 eV
10 eV
Which of the following acts as a donor impurity in doping process ?
Arsenic
Indium
Gallium
Boron
Conductivity of semiconductor __________________ with increase in temperature.
increases
decreases
remains unchanged
This is a graph that is seen on CRO. How is it change after full wave rectification process?
Who contribute to the current in a semiconductor
electrons only
holes only
negative ions
both electrons and holes
Identify the n-doped crystal lattice.
Holes in n-type materials are called
majority carrier
minority carrier
diffusion current
hole current
The current in a semiconductor is produced by
electron only
holes only
negative ions
both electrons and holes
A pn junction is formed by
the recombination of electrons and holes
ionization
the boudary of a p-type and an n-type material
the collision of a proton and a neutron
X-plates is
positioned vertically to deflect the electron beam in horizontal direction
positioned horizontally to deflect the electron beam in vertical direction
Diagram shows part of C.R.O. What is Q?
Control grid
Focusing anode
Accelerating anode
Cathode
What you need to control in order to adjust the resolution (sharpness) of the signal in C.R.O.?
Control grid
Focusing anode
Accelerating anode
Cathode
Which of the following is wrong about the uses of C.R.O.?
To measure potential difference
To measure short time intervals
To display waveforms
To measure current
What is the function of time-base knob on C.R.O.?
To control brightness of the bright spot
To control the sharpness of the bright spot
To control the magnitude of vertical deflection of the bright spot
To control the magnitude of horizontal deflection of the bright spot
Tick the statement about uses of CRO. Your answer may have more than 1.
measure potential difference using the C.R.O.
measure short time intervals using the C.R.O.
display wave forms using the C.R.O.
Which particle is cathode ray?
Electron beam
Gamma ray
Neutron
Alpha particles
Process of emission of electrons from hot metal surfaces is called .................
photoelectric effect
thermionic emission
static emission
emission current
One of the properties of cathode rays is ...............
positive charge
does not move in a straight line
can be deflected by electrical field
cannot be deflected by magnetic field
If an electric field is put across the beam with the positive plate on top and the negative plate below.
The beam will bend ...............
Up
down
left
right
in a circle
Why is a vacuum needed in the tube?
It makes the process more efficient.
It impedes or slows down the electrons.
It allows the electrons to flow unimpeded.
It allows the electrons to be made into a beam.
How is the electron beam detected?
Use of a fluorescent screen.
By deflecting the beam of electrons with a magnetic field.
By deflecting the beam of electrons with an electric field.
Using an electron microscope.
how to increase the rate of thermionic emission
immerse metal in an electrolyte
increase the surrounding pressure
decrease the temperature of metal to stabilize electron
increase the surface area of the metal
What can be used to control the direction of the cathode ray?
electrical field
gravitational field
heat energy
quantum field
What is the purpose of connecting anode with high voltage d.c power supply?
to deflect or change the direction of the electron
to accelerate the electron
to deceleration the electron
to increase the rate of thermionic emission
Figure shows two pulses on a CRO. The pulses are caused by two consecutive signals detected by a microphone connected to the CRO.
Calculate the time lapse between the signals if the timebase setting is 4 ms cm -1.
1.208 second
0.1208 second
0.00208 second
0.0208 second
Diagram shows a trace on the screen of a C.R.O. when a signal is connected across the Y-input. What type of signal is applied across the Y-input and what is the condition of the time-base?
alternating current, switched off
direct current, switched off
alternating current, switched on
direct current, switched on
Diagram shows a waveform displayed on the screen of a cathode ray oscilloscope (C.R.O.). Which of the following control switch needs to be switched on to display this waveform?
intensity
time-base
Y-gain
Y-shift
Diagram shows the trace displayed on the screen of a C.R.O. with the time-base set to 10 ms/div. What is the frequency, f of the wave?
5 Hz
25 Hz
40 Hz
50 Hz
Diagram shows a waveform displayed on the screen of a C.R.O. If the controls on the C.R.O. are set at 0.5 V/div and 2 ms/div, find the peak voltage and the frequency of the input signal.
4 V, 2 Hz
5 V, 10 Hz
2 V, 100 Hz
4 V, 100 Hz
