About $$5$$% of the power of a $$100$$ W light bulb is converted to visible radiation. What is the average intensity of visible radiation at a distance of $$1$$ m from the bulb?
1. $$0.472$$ W/m2
2. $$0.398$$ W/m2
3. $$0.323$$ W/m2
4. $$0.401$$ W/m2

Subtopic:  Particle Nature of Light |
62%
From NCERT
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

Monochromatic light of wavelength $$632.8~\text{nm}$$ is produced by a helium-neon laser. The power emitted is $$9.42~\text{mW}$$. The energy of each photon in the light beam is:
1. $$4.801 \times 10^{-19}~\text{J}$$
2. $$2.121 \times 10^{-19}~\text{J}$$
3. $$5.043 \times 10^{-19}~\text{J}$$
4. $$3.141 \times 10^{-19}~\text{J}$$

Subtopic:  Particle Nature of Light |
60%
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 energy flux of sunlight reaching the surface of the earth is $$1.388\times10^{3}$$ W/m2. How many photons (nearly) per square meter are incident on the Earth per second? Assume an average wavelength of $$550~\text{nm}$$.
1. $$3.84\times10^{21}$$
2. $$2.97\times10^{21}$$
3. $$4.12\times10^{21}$$
4. $$2.10\times10^{21}$$

Subtopic:  Particle Nature of Light |
65%
From NCERT
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 $$100$$ W sodium lamp radiates energy uniformly in all directions. The lamp is located at the center of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of sodium light is $$589$$ nm. What is the energy per photon associated with the sodium light?
1. $$1.21$$ eV
2. $$2.21$$ eV
3. $$2.11$$ eV
4. $$1.11$$ eV

Subtopic:  Particle Nature of Light |
62%
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

In an accelerator experiment on high-energy collisions of electrons with positrons, a certain event is interpreted as the annihilation of an electron-positron pair of total energy 10.2 BeV into two γ-rays of equal energy. What is the wavelength associated with each γ-ray? (1BeV = 109 eV)

1.  $$3.4 \times10^{-16}$$ m
2. $$1.7 \times10^{-16}$$ m
3. $$2.4 \times10^{-16}$$ m
4. $$3.1 \times10^{-16}$$ m

Subtopic:  Particle Nature of Light |
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints