MCQ
For which frequency of light, the human eye is most sensitive?
  • A
    55.405 × 1014 Hz
  • B
    95.405 × 1014 Hz
  • C
    5.405 × 1014 Hz
  • D
    79.405 × 1014 Hz

Answer

  1. 5.405 × 1014 Hz

Explanation:

Human eye is sensitive to light of wavelength ➔ $\lambda$ = 5550 angstrom.

So its frequency is $\text{v}=\frac{\text{c}}{\lambda}$

$\text{v} =\frac{5550}{3 × 10^8} × 10^{-10}$

v = 5.405 × 1014 Hz

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A dielectric slab is inserted between the plates of an isolated charged capacitor. Which of the following quantities will remain the same?

A passenger in an aeroplane shall:

The focal length of the objective of a compound microscope if fo and its distance from the eyepiece is L. The object is placed at a distance u from the objective. For proper working of the instrument:
  1. L < u
  2. L > u
  3. fo < L < 2fo
  4. L > 2fo

A spherical conductor of radius 2m is charged to a potential of 120 V. It is now placed inside another hollow spherical conductor of radius 6m. Calculate the potential to which the bigger sphere would be raised

(a) 20 V

(b) 60 V

(c) 80 V

(d) 40 V

A long, straight wire carries a current i. The magnetizing field intensity H is measured at a point P close to the wire. A long, cylindrical iron rod is brought close to the wire so that the point P is at the centre the rod. The value of H at P will:
  1. Increase many times.
  2. Decrease many times
  3. Remain almost constant.
  4. Become zero.
A point source of light is used in a photoelectric effect. If the source is removed farther from the emitting metal, the stopping potential:
  1. Will increase.
  2. Will decrease.
  3. Will remain constant.
  4. Will either increase or decrease.

A particle is moving in a uniform magnetic field, then

(a) Its momentum changes but total energy remains the same

(b) Both momentum and total energy remain the same

(c) Both will change

(d) Total energy changes but momentum remains the same

A heavenly body is receding from earth such that the fractional change in l is 1, then its velocity is

(a) C

(b)  

(c)   

(d)  

A monochromatic beam of light falls on YDSE apparatus at some angle (say q) as shown in figure. A thin sheet of glass is inserted in front of the lower slit S2. The central bright fringe (path difference = 0) will be obtained

(a) At O

(b) Above O

(c) Below O

(d) Anywhere depending on angle q, thickness of plate t and refractive index of glass m

A thin slice is cut out of a glass cylinder along a plane parallel to its axis. The slice is placed on a flat glass plae as shown in figure. The observed interference fringes from this combination shall be: