Continuous Spectrum

Q. In a Coolidge tube experiment, the cutoff wavelength for the observed x ray was found to be 25 pm. This means x rays with wavelengths greater than this won't be present; only x rays whose wavelength is less than 25 pm will be received.

1. True
2. False

Q. The number of waves completed by an electron in one complete revolution in 5^th orbit of He⁺ ion is

He⁺ आयन की 5^th कक्षा में एक पूर्ण परिक्रमण में इलेक्ट्रॉन द्वारा निर्मित तरंगों की संख्या है

1. 5
2. 6
3. 4
4. 25

Q. The wavelength of the first line of Balmer series is $6563\mathring{\text{A}}$. The wavelength of the first line of Lyman series will be

1. $7500\mathring{\text{A}}$
2. $600\mathring{\text{A}}$
3. $1215\mathring{\text{A}}$
4. $2500\mathring{\text{A}}$

Q.

An X-ray tube is operated at 66 kV. Then, in the continuous spectrum of the emitted X-rays

1. wavelengths 0.01 nm and 0.02 nm will both be present
2. wavelengths 0.01 nm and 0.02 nm will both be absent
3. wavelength 0.02 nm will be absent but wavelength 0.01 nm will be present
4. wavelength 0.01 nm will be absent but wavelength 0.02 nm will be present

Q.

An X-ray tube is operated at 66 kV. Then, in the continuous spectrum of the emitted X-rays

1. wavelengths 0.01 nm and 0.02 nm will both be present
2. wavelengths 0.01 nm and 0.02 nm will both be absent
3. wavelength 0.02 nm will be absent but wavelength 0.01 nm will be present
4. wavelength 0.01 nm will be absent but wavelength 0.02 nm will be present

Q.

Consider a photon of continuous X-ray coming from a Coolidge tube. Its energy comes from

1. The kinetic energy of the striking electron

2. The kinetic energy of the free electrons of the target

3. The kinetic energy of the ions of the target

4. An atomic transition in the target

Q.

A potential difference of 20 kV is plied across and X - ray tube. The minimum wavelength of X-rays generated is ___Å. (IIT JEE 1996)

Q.

In an X-ray tube, electrons accelerated through a very high potential difference strike a metal target. If the potential difference is increased, the speed of the emitted X-rays

1. increases

2. decreases

3. increases or decreases depending on the target material

4. is always equal to $3\times {10}^{8}m{s}^{-1}$