Heat travels through vacuum by 
(1) Conduction                 

(2) Convection

(3) Radiation                     

(4) Both (a) and (b)

Subtopic:  Radiation |
 80%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Taking into account the radiation that a human body emits which of the following statements is true?

1. The radiation is emitted only during the day.
2. The radiation is emitted during the summers and absorbed during the winters.
3. The radiation emitted lies in the ultraviolet region and hence is not visible.
4. The radiation emitted is in the infra-red region.
Subtopic:  Radiation |
 59%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by

(1) Wien’s law                               

(2) Rayleigh  law

(3) Planck’s law of radiation             

(4) Stefan’s law of radiation

Subtopic:  Radiation |
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Pick out the statement which is not true .

(1) IR radiations are used for long distance photography

(2) IR radiations arise due to inner electron transitions in atoms

(3) IR radiations are detected by using a bolometer

(4) Sun is the natural source of IR radiation

Subtopic:  Radiation |
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A hot and a cold body are kept in vacuum separated from each other. Which of the following cause decrease in temperature of the hot body ?

(1) Radiation

(2) Convection

(3) Conduction

(4) Temperature remains unchanged

Subtopic:  Radiation |
 82%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

For a perfectly black body, its absorptive power is

(1) 1                 

(2) 0.5

(3) 0                 

(4) Infinity

Subtopic:  Radiation |
 84%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Certain substance emits only the wavelengths λ1, λ2, λ3 and λ4 when it is at a high temperature. When this substance is at a colder temperature, it will absorb only the following wavelengths ?
(a) λ1                      (b) λ2
(c) λ1 and λ2          (d)  λ1, λ2, λ3 and λ4

Subtopic:  Radiation |
 81%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

As compared to the person with white skin, the person with black skin will experience 
(1) Less heat and more cold           

(2) More heat and more cold

(3) More heat and less cold             

(4) Less heat and less cold

Subtopic:  Radiation |
 59%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Relation between emissivity e and absorptive power a is (for black body)
(1) e = a                     

(2) e=1a

(3) e=a2                    

(4) a=e2

Subtopic:  Radiation |
 75%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

Which of the following statements is wrong ?

(1) Rough surfaces are better radiators than smooth surface

(2) Highly polished mirror like surfaces are very good radiators

(3) Black surfaces are better absorbers than white ones

(4) Black surfaces are better radiators than white

Subtopic:  Radiation |
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh