Radiography Quiz

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary unit of current intensity?

Volt

Coulomb

Ampere (correct)

Watt

What does one ampere represent in terms of the electromagnetic unit?

1 EMU

10 EMUs

0.1 EMUs (correct)

100 EMUs

At what temperature is absolute zero in the Kelvin scale?

0 K

-273 °C (correct)

-273 K

273 °C

What physical quantity does the unit 'candela' measure?

Luminous intensity Signup and view all the answers

Which of the following statements about derived units is correct?

Derived units can only be expressed in terms of fundamental units. Signup and view all the answers

What is the relationship between a coulomb and an ampere?

1 Coulomb = 1 Ampere x 1 Second Signup and view all the answers

Which of the following quantities is NOT considered a fundamental unit?

Power Signup and view all the answers

How is the boiling point of water expressed in Kelvin?

373 K Signup and view all the answers

What type of rays are emitted as a positively charged particle during radioactive decay?

Alpha rays Signup and view all the answers

Which of the following statements is true about B rays?

They are stream of electrons. Signup and view all the answers

What is the primary characteristic of Y rays compared to Alpha and B rays?

They are electromagnetic waves. Signup and view all the answers

Which property of X-rays allows them to cause ionization of gases?

Their penetrating power. Signup and view all the answers

What did Wilhelm Conard Roentgen discover in 1895?

X-rays while studying high voltage discharge. Signup and view all the answers

What are the two parts that make up the measurement of any physical quantity?

Numeric part and unit Signup and view all the answers

What is the approximate range of wavelengths for X-rays?

0.1-0.5 Å Signup and view all the answers

How is the distance of the moon measured indirectly?

Sending radar signals and measuring the time for the echo Signup and view all the answers

What effect do X-rays have on silver halide crystals?

They chemically change them. Signup and view all the answers

Which of the following is a universally accepted characteristic of a physical standard?

It should be easily reproducible Signup and view all the answers

Which property differentiates X-rays from visible light rays?

X-rays cannot be focused by a lens. Signup and view all the answers

What is the speed of the signal used to measure the distance of the moon?

3 x 10^8 m/second Signup and view all the answers

Which system of units is utilized in the International System of Units (SI)?

Metre - kilogram - second Signup and view all the answers

What is the distance represented by 1 parsec in meters?

3.08 x 10^16 m Signup and view all the answers

Which length measurement is smallest?

Fermi Signup and view all the answers

In the provided formula for measuring distance, what does 's' represent?

Distance of the moon Signup and view all the answers

What percentage of kinetic energy is converted to X-rays at 60 kVp?

0.5% Signup and view all the answers

How does the production of heat in the anode change with an increase in tube current?

It increases directly. Signup and view all the answers

What is the term for a substance that readily releases electrons when heated?

Thermionic emitter Signup and view all the answers

At what kVp does the efficiency of X-ray production begin to markedly increase?

100 kVp Signup and view all the answers

What process is responsible for the release of electrons from a material when it is heated?

Thermionic emission Signup and view all the answers

Which factor is NOT related to the efficiency of X-ray production?

Tube current Signup and view all the answers

What causes the outer shell electrons to be more easily dislodged from an atom compared to inner electrons?

They are more loosely bound. Signup and view all the answers

What type of radiation is produced when an energetic electron comes close to the nucleus of an atom?

Bremsstrahlung radiation Signup and view all the answers

What is the relationship between kVp and the kinetic energy of electrons in an X-ray tube?

Kinetic energy increases as kVp increases. Signup and view all the answers

How is the energy of a 70 keV electron expressed in joules?

$1.12 imes 10^{-14} J$ Signup and view all the answers

What happens to high-speed electrons upon colliding with the target atom in an X-ray tube?

They convert kinetic energy into thermal and electromagnetic energy. Signup and view all the answers

What is the approximate velocity of an electron arriving at the target with 70 keV energy?

$1.6 imes 10^{7} m/sec$ Signup and view all the answers

What occurs to the outer shell electrons of the target atom during interaction with high-speed electrons?

They are raised to an excited state without ionization. Signup and view all the answers

What is the primary effect of raising the tube current (mA) in an X-ray tube?

Increasing the number of electrons reaching the target. Signup and view all the answers

What is the typical distance between the filament and the target in an X-ray tube?

1 to 3 cm Signup and view all the answers

At what limit does the speed of electrons approach when influenced by higher voltages?

The speed of light Signup and view all the answers

What happens to the resistance of a conductor as the current flowing through it increases?

Resistance increases due to heating. Signup and view all the answers

Which of the following correctly defines superconductors?

Substances that offer no resistance to current flow. Signup and view all the answers

Why do superconductors lose electrical resistivity?

Because electrons form cooperative clouds at low temperatures. Signup and view all the answers

How does alternating current (AC) differ from direct current (DC)?

AC's magnitude and direction change periodically. Signup and view all the answers

What is the relationship between peak voltage and current in AC and DC circuits regarding heat generation?

DC requires twice the current of AC to generate the same heat. Signup and view all the answers

What are non-ohmic substances?

Substances that do not obey Ohm's law. Signup and view all the answers

At what temperature range do certain conductors start exhibiting high conductivity?

Near absolute zero, specifically below 10 K. Signup and view all the answers

How does increasing temperature affect the conductivity of a typical conductor?

Conductivity decreases as temperature rises. Signup and view all the answers

Study Notes

Unit I - Measurement

Physical quantities are expressed in terms of magnitude and unit.
Measurement consists of a numeric value and a unit.
Length measurement can be direct (using a ruler) or indirect (using radar signals).
Common units for length include Fermi, Angstrom, light-year, and parsec.
1 Fermi = 1.0 x 10⁻¹⁵ meters
1 Angstrom = 10⁻¹⁰ meters
1 Light year = 9.46 x 10¹⁵ meters
1 Parsec = 3.08 x 10¹⁶ meters

Basic Absolute Systems of Units

Common systems include CGS, MKS, SI, and FPS.
CGS uses centimeters, grams, and seconds.
MKS uses meters, kilograms, and seconds.
SI is the International System of Units, adopted worldwide.

Fundamental and Derived Units

Fundamental units are the base units for expressing physical quantities.
Derived units are derived from these fundamental units.
Seven fundamental units include length, mass, time, temperature, electric current, luminous intensity, and amount of substance.

Atomic Structure and Properties

Atoms consist of a nucleus surrounded by orbiting electrons.
The nucleus contains protons (positive charge) and neutrons (no charge).
Isotopes have the same atomic number but different mass numbers.
Isobars have the same mass number but different atomic numbers.

Electromagnetic Induction

Induced EMF is produced when the magnetic field around a coil changes.
Faraday's first law states that a changing magnetic flux induces an EMF.
Faraday's second law states that the magnitude of induced EMF is proportional to the rate of change of magnetic flux.
Lenz's Law: The direction of an induced current opposes the change that produced it.

Current and Resistance

Electrical current is the rate of flow of electrical charge.
Ohm's Law: The current flowing through a conductor is directly proportional to the potential difference across its ends, given the temperature remains the same.
Resistance is a material's opposition to current flow.
Conductors have low resistance, insulators have high resistance.
Superconductors have zero resistance.

Electric Power, Ammeter, and Voltmeter

Electric power is the rate of consumption of electric energy.
Ammeters measure electrical current.
Voltmeters measure electrical potential difference.

Production of X-rays

X-rays are produced when fast-moving electrons strike a target (anode) in an X-ray tube.
The kinetic energy of the electrons is converted into X-rays, and heat.
Thermionic emission is the process of emitting electrons from a heated filament.
High voltage accelerates electrons toward the target.

Transformer Law, Circuit Design

Voltage ratio in a transformer is proportional to the turns ratio.
Transformers step up or down voltage based on the turns ratio.
Rectifiers convert alternating current (AC) to direct current (DC).
High-frequency generators produce almost constant potential across the X-ray tube.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.