A Mass M =50g Is Dropped On A Vertical Spring Of Spring Constant 500 N/m From A Height H  =10 Cm As Shown In Figure. The Mass Sticks To The Spring And Executed Simple Harmonic Oscillations After That. A Concave Mirror Of Focal Length 12 Cm Facing The Mass Is Fixed With Its Principal Axis Coinciding With The Line Of Motion Of  the Mass, Its Pole Being At A Distance Of 30 Cm From The Free End Of The Spring. Find The Length In Which The Image Of The Mass Oscillated                                                                                                    

Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.




A mass m =50g is dropped on a vertical spring of spring constant 500 N/m from a height h  =10 cm as shown in figure. The mass sticks to the spring and executed simple harmonic oscillations after that. A concave mirror of focal length 12 cm facing the mass is fixed with its principal axis coinciding with the line of motion of  the mass, its pole being at a distance of 30 cm from the free end of the spring. Find the length in which the image of the mass oscillated



Correct option is

1.24 cm


mg = kx

Now mean position at 30 + 0.1 = 30.1 cm from mirror   


          Mg (n + y) = 1/2 ky2


          u1 = – 31.5 cm,        – (31.5 – 30.1) =  – 1.4 cm

          f = – 12 cm            f = – 12 cm, u2 = 30.1 – 1.4 = – 28.7 cm








Light is incident normally on the short face of a 30o – 60o – 90oprism. A liquid is poured on the hypotenuse of the prism. If the refractive index of the prism is √(3,) find the maximum refractive index of the liquid so that light is totally reflected




A ray of light passing through a prism having refractive index √(2) suffers minimum deviation. It is found that the angle of incidence is double the angle of refraction within the prism. what is the angle of prism?


 In a glass sphere, there is a small bubble 2 ×10-2 m from its centre. If the bubble is viewed along a diameter of the sphere, from the side on which it lies, how far from the surface will it appear? The radius of glass sphere is 5 ×10-2 m and refractive index of glass is 1.5



Considering normal incidence of ray, the equivalent refractive index of combination of two slabs shown in figure is



A ray of light falls on a transparent glass slab of refractive index 1.62. What is the angle of incidence, if the reflected ray and refracted ray are mutually perpendicular?



Calculate the refractive index of glass with respect to water. It is given that refractive indices of glass and water with respect to air are 3/2 and 4/3 respectively


The refractive index of the medium, if a light wave has a frequency of  and a wavelength of  metres in a medium, will be


A small object is placed at the centre of the bottom of a cylindrical vessel of radius 3 cm and height 4 cm filled completely with water, Consider the ray leaving the vessel through a corner. Suppose this ray and the ray along the axis of the vessel are used to trace the image. Find the apparent depth of the image and the ratio of real depth to the apparent depth under the assumptions taken. Refractive index of water = 1.33




A convex lens has a focal length of 10 cm. Find the location and nature of the image if  point object is placed on the principal axis at a distance of (a) 9.8 cm, (b) 10.2 cm from the lens.


Consider the situation shown in figure. The elevator is going up with an acceleration of 2.00 m/s2 and the focal length of the mirror is 12.0 cm. All the surfaces are smooth and the pulley is light. The mass – pulley system is released from rest (with respect to the elevator ) at t = 0 when the distance of B from the mirror is 42.0 cm. find the distance between the image of the block B and the mirror at t = 0.200 s. Take g = 10 m/s2