X-ray Tube Quiz

What is the primary function of the cathode in an X-ray tube?

• To generate electrons

• To stop X-ray production

• To absorb excess radiation

• To cool down the X-ray tube

Answer explanation

The primary function of the cathode in an X-ray tube is to generate electrons. These electrons are then accelerated towards the anode, where they produce X-rays upon collision.

Which process occurs at the filament inside the cathode?

• Bremsstrahlung radiation

• Thermionic emission

• X-ray absorption

• Photoelectric effect

Answer explanation

Thermionic emission is the process where electrons are emitted from a heated filament inside the cathode. This occurs when the thermal energy is sufficient to overcome the work function of the material.

What is the purpose of the anode in an X-ray tube?

• To produce electrons

• To stop the electron flow

• To accelerate electrons towards the cathode

• To convert electron energy into X-rays

Answer explanation

The anode in an X-ray tube serves to convert the kinetic energy of accelerated electrons into X-rays. When electrons collide with the anode, their energy is transformed into X-ray photons, which are essential for imaging.

Why is a vacuum necessary inside an X-ray tube?

• To allow free movement of electrons

• To improve image quality

• To prevent overheating

• To increase X-ray absorption

Answer explanation

A vacuum is necessary inside an X-ray tube to allow free movement of electrons. Without a vacuum, air molecules would impede the flow of electrons, reducing the efficiency of X-ray production.

Which of the following materials is commonly used for the anode target?

• Aluminum

• Copper

• Tungsten

• Silver

Answer explanation

Tungsten is commonly used for the anode target due to its high melting point and excellent thermal conductivity, making it ideal for high-energy applications. Aluminum, copper, and silver do not possess the same thermal properties.

What happens when electrons strike the anode target?

• They bounce back to the cathode

• They produce heat and X-rays

• They generate an electric current

• They get absorbed completely

Answer explanation

When electrons strike the anode target, they interact with the material, resulting in the production of heat and X-rays. This is a key process in X-ray generation, making the correct answer 'They produce heat and X-rays'.

What percentage of the energy produced in an X-ray tube is converted into X-rays?

• 1%

• 10%

• 50%

• 90%

Answer explanation

Only about 1% of the energy produced in an X-ray tube is converted into X-rays, while the rest is lost as heat and other forms of radiation. Therefore, the correct answer is 1%.

What is the function of the glass envelope in an X-ray tube?

• To prevent heat loss

• To protect the components and maintain a vacuum

• To absorb harmful radiation

• To provide power to the cathode

Answer explanation

The glass envelope in an X-ray tube serves to protect the internal components from damage and to maintain a vacuum, which is essential for the efficient production of X-rays.

Which cooling method is commonly used to prevent overheating of the anode?

• Air cooling

• Water circulation

• Oil immersion

• Heat sink and rotation

Answer explanation

The heat sink and rotation method effectively dissipates heat from the anode, preventing overheating. This method enhances cooling efficiency compared to air cooling, water circulation, or oil immersion.

Why is tungsten used as the anode target material in an X-ray tube?

• It has a low melting point.

• It absorbs radiation efficiently.

• It has a high atomic number and melting point.

• It produces low-energy X-rays.

Answer explanation

Tungsten is used as the anode target material in X-ray tubes because it has a high atomic number, which increases X-ray production efficiency, and a high melting point, allowing it to withstand the heat generated during operation.