Which of the following is not the property of cathode rays:

1. it produces a heating effect.
2. it does not deflect in the electric field.
3. it casts a shadow.
4. it produces fluorescence.
Subtopic:  Electron Emission |
 67%
From NCERT
AIPMT - 2002
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

J.J. Thomson's cathode-ray tube experiment
demonstrated that:
1. cathode rays are streams of negatively charged ions.
2. all the mass of an atom is essentially in the nucleus.
3. the \(\frac{e}{m}\) of electrons is much greater
than the \(\frac{e}{m}\) of protons.
4. the \(\frac{e}{m}\) ratio of the cathode ray particles changes when a different gas is
placed in the discharge tube.
Subtopic:  Electron Emission |
 54%
From NCERT
AIPMT - 2003
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

A monochromatic source of light emits \(50~\text{W}\) at a wavelength of \(400~\text{nm}\). The number of photons emitted per second is approximately (Take \(\text{hc} = 1240~\text{eV-nm}\)):
1. \(10^{20}\) 
2. \(10^{25}\)
3. \(10^{30}\)
4. \(10^{40}\)
Subtopic:  Particle Nature of Light |
 81%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

A photo-cell is illuminated by a source of light, which is placed at a distance \(d\) from the cell. If the distance becomes \(\dfrac{d}{2}\), then the number of electrons emitted per second will be: 
1. same
2. four times
3. two times
4. one-fourth

Subtopic:  Photoelectric Effect: Experiment |
 70%
From NCERT
AIPMT - 2001
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The maximum kinetic energy of the emitted photoelectrons in photoelectric effect is independent of:
1. work function of material
2. intensity of incident radiation
3. frequency of incident radiation
4. wavelength of incident radiation
Subtopic:  Photoelectric Effect: Experiment |
 77%
From NCERT
NEET - 2023
Please attempt this question first.
Hints
Please attempt this question first.

The wavelength of light in the visible region is about \(550\) nm (average wavelength) for yellow-green colour. Three materials with work functions are given as Al (\(4.28\) eV), Cu (\(4.65\) eV) and Na (\(2.75\) eV). From which of these photosensitive materials, can you build a photoelectric device that operates with visible light?
1. Al
2. Cu
3. Na
4. none of the above

Subtopic:  Photoelectric Effect: Experiment |
 53%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
Links
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

advertisementadvertisement

A metallic ball (work function: \(2\) eV) is irradiated with light consisting of photons of wavelength \(200\) nm. The ball has an initial charge, giving it a potential \(1\) V. Take the product of Planck's constant and velocity of light, hc as \(1240\) eV-nm. The final potential of the ball, when photoemission practically stops, is: 
1. \(2\)
2. \(3.2\)
3. \(4.2\)
4. \(5.2\) V
Subtopic:  Photoelectric Effect: Experiment |
 53%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

A fraction \(f\) of the incident energy in a beam of light of wavelength \(\lambda\) is absorbed by a metallic surface and causes photoemission. If the power of the beam falling on the surface is \(P\), then the maximum photocurrent is (\(e\) is electronic charge, \(h\) is Planck's Constant, \(c\) is the velocity of light in vaccum):
1. \(\dfrac{\lambda{P}}{h c} f\)

2. \(\dfrac{2\lambda{P}}{h c} f\)

3. \(\dfrac{\lambda{P}}{h c} f e\)

4. \(\dfrac{2\lambda{P}}{h c} f e\)
Subtopic:  Photoelectric Effect: Experiment |
 57%
From NCERT
Please attempt this question first.
Hints
Please attempt this question first.

A source of light is placed at a distance of \(50\) cm from a photocell and the stopping potential is found to be \(V_0\). If the distance between the light source and photocell is made \(25\) cm, the new stopping potential will be: 
1. \(V_0 /2\) 2. \(V_0 \)
3. \(4V_0 \) 4. \(2V_0 \)
Subtopic:  Photoelectric Effect: Experiment |
 74%
From NCERT
NEET - 2013
Please attempt this question first.
Hints
Please attempt this question first.

advertisementadvertisement

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is:

1.   2.
3. 4.
Subtopic:  Einstein's Photoelectric Equation |
 77%
From NCERT
AIPMT - 2004
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch