Which one of the following statements about X-rays is not true ?
They have wavelengths of about 1 Å.
These can be generated by bombarding a metal target by high energy electrons.
Due to their wavelengths being shorter, these can be used for radar systems.
These are also used for the treatment of certain forms of cancer.
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-1 – 2023
A) They have wavelengths of about 1 Å. X-rays are part of the electromagnetic spectrum with wavelengths typically ranging from 0.01 to 10 nanometers (0.1 to 100 Å). So, a wavelength of 1 Å falls within this range. This statement is true.
B) These can be generated by bombarding a metal target by high energy electrons. This is the standard method for producing X-rays in an X-ray tube (using bremsstrahlung radiation and characteristic X-ray emission). This statement is true.
C) Due to their wavelengths being shorter, these can be used for radar systems. Radar systems work by transmitting electromagnetic waves and detecting the reflected signals. They typically use radio waves or microwaves (wavelengths from centimeters to meters). X-rays have much shorter wavelengths and high energy, which makes them highly penetrating. They are not suitable for radar applications, which rely on reflection from objects in the atmosphere or space. This statement is NOT true.
D) These are also used for the treatment of certain forms of cancer. High-energy X-rays are a common form of radiation therapy used to kill cancer cells. This statement is true.
Therefore, the statement that is not true about X-rays is C.