MCQ
The wavelength of which colour is minimum ?
  • Violet
  • B
    Yellow
  • C
    Blue
  • D
    Red

Answer

Correct option: A.
Violet
A

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

Out of the following, waves of which frequency can penetrate ionosphere?
The ratio of magnetic fields due to a smaller bar magnet in the end on position to broad side on position is:
According to Maxwell’s hypothesis, a changing electric field gives rise to(a) An e.m.f.(b) Electric current(c) Magnetic field(d) Pressure radiant
       
A particle moves on a straight line with a uniform velocity. Its angular momentum:
  1. Is always zero.
  2. Is zero about a point on the straight line.
  3. Is not zero about a point away from the straight line.
  4. About any given point remains constant.
Eddy currents are used in(a) Induction furnace(b) Electromagnetic brakes(c) Speedometers(d) All of these
   
   
The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be(a) Horizontal(b) Vertical(c) Clockwise(d) Anticlockwise
       
An infinitely long conductor $\text{PQR}$ is bent to form a right angle as shown. A current $I$ flows through $\text{PQR}$ The magnetic field due to this current at the point $M$ is $\mathrm{H}_1$. Now another infinitely long straight conductor $QS$ is connected at $Q$ so that the current is $\mathrm{I} / 2$ in $QR$ as well as in $QS ,$ The current in $PQ$ remaining unchanged. The magnetic field at $M$ is now $\mathrm{H}_2$. The ratio $\mathrm{H}_1 / \mathrm{H}_2$ is given by

 
Intensity of magnetic field due to earth at a point inside a hollow steel box is(a) Less than outside(b) More than outside(c) Same(d) Zero
       
Out of dia, para and ferromagnetism, the universal property of all substances is:
A man can see the objects upto a distance of one metre from his eyes. For correcting his eye sight so that he can see an object at infinity, he requires a lens whose power is(a) + 0.5 D(b)  + 1.0 D  (c) + 2.0 D(d)  – 1.0 D