STATEMENT-1
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-rays do not change.
because
STATEMENT-2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.
If the accelerating potential in an X-ray tube is increased, the wavelengths of the characteristic X-rays do not change.
because
STATEMENT-2
When an electron beam strikes the target in an X-ray tube, part of the kinetic energy is converted into X-ray energy.
- (A)Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1
- (B)Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1✓ Correct
- (C)Statement-1 is True, Statement-2 is False
- (D)Statement-1 is False, Statement-2 is True
Answer: (B)
Solution
Statement-1: Characteristic X-rays are produced when inner-shell electrons of the target atoms are knocked out and outer electrons transition to fill the vacancy. The wavelengths of these X-rays depend only on the energy level differences in the target atoms, which are fixed properties of the element. Increasing the accelerating potential does not change these energy levels, so the wavelengths of characteristic X-rays remain constant. Statement-1 is True.
Statement-2: When electrons strike the target, their kinetic energy is indeed converted into X-ray energy (both continuous and characteristic X-rays). Statement-2 is True.
Relationship: However, Statement-2 is a general fact about X-ray production and does not specifically explain why characteristic X-ray wavelengths are independent of accelerating potential. The explanation lies in the atomic energy levels being fixed. Therefore, Statement-2 is NOT a correct explanation for Statement-1.
The answer is (B).
Statement-2: When electrons strike the target, their kinetic energy is indeed converted into X-ray energy (both continuous and characteristic X-rays). Statement-2 is True.
Relationship: However, Statement-2 is a general fact about X-ray production and does not specifically explain why characteristic X-ray wavelengths are independent of accelerating potential. The explanation lies in the atomic energy levels being fixed. Therefore, Statement-2 is NOT a correct explanation for Statement-1.
The answer is (B).
JEE Advanced · 2007 · 08 Apr 2007 · Paper 1 · Single correct option