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The photoelectric work function of a metal surface is 2eV.When light of frequency 1.5x1015Hz is incident on it,the maximum kinetic energy of the photo electrons approximately is

When a metal surface is illuminated by a light of wavelength 400 nm and 250 nm The maximum velocities of the photo electrons ejected are v and 2v respectively.The work function of the metal is : (h= Planck's constant, C= velocity of light in air)

A double convex lens of focal length 30cm is made of glass of R.I.1.6. When it is immersed in a liquid, the focal length is found to be 90cm. The R.I of the liquid is

The work function of the nickel is 5 eV. When a light of wavelength 2000 Ao falls on it, it emits photo electrons in the circuit. Then the potential difference necessary to stop the fastest electrons emitted is (given h = 6.67 x 10-34 J-s)

Fraunhofer lines are produced by the absorption of light in :

Photons of energy 2.0 eV and wavelength λ fall on a metal plate and release photoelectrons with a maximum velocity v.By decreasing X by 25% the maximum velocity of photoelectrons is doubled. The work function of the material of the metal plate,in eV is:

The refractive index of the material of a double convex lens is 1.5 and its focal length is 5 cm. If the radii of curvature are equal, the value of the radius of curvature (in cm) is

A convex lens of focal length 0.15m is made of a material of refractive index 3 / 2. When it is placed in a liquid, its focal length is increased by 0.225 m. The refractive index of the liquid is

If c is velocity of light in fre space,the time taken by the light to travel a distance x in a medium of refractive index μ is given by:

The ratio of effective focal length of Huygens eye piece and the object distance of its field lens is

Which of the following statements is not true in the case of 1 Huygen's eye piece

A magnifying glass is made of a combination of convergent lens of power +20 diopters and a divergent lens of power -4 diopters .If the image is formed atleast distance of distinct vision (25cm), the magnifying power is

A motor of power P0 is used to deliver water at a certain rate through a given horizontal pipe. To increase the rate of flow of water through the same pipe n times, the power of the motor is increased to P1 The ratio of P1 to P0 is

X-rays of energy 50 KeV are scattered from a carbon target. The scattered rays are detected at 900 from the incident beam. the percentage change in wave length approximately [mo=9.0x10-31kg, c=3x108 m/sec] is

Two lenses of focal lengths +10cm, and -15cm when put in contact behave like a convex lens .They will have zero longitudinal chromatic aberration if their dispersive powers are in the ratio

The focal length of a lens of dispersive power 0.45 which should be placed in contact with a convex lens of focal length 84 cm and dispersive power 0.21 to make the achromatic combination from the two lenses, in cm is

A ray of light undergoes deviation of 300 when incident on an equilateral prism of refractive index√2.What is the angle of the ray inside the prism with the base of the prism?

The least distance of distinct vision is 25cm. If the focal length of convex lens is 10 cm. It acts as a simple microscope of maximum magnification

Dispersive power depends on the following :

The following phenomenon which is not explained by Huygens construction of wave front is

The angle of a prism is 600 and the angle of minimum deviation of light passing through it is observed to be 400. The angle of incidence of light is

In a prism, the effective indices of different colors are μv=1.6;μR=1.52;μr=1.56.The dispersive power of the prism is

According to Moselay's law, the frequency of (v) of the Kα - line and the atomic number (Z) of the element have the relation (A and B are constants)

The focal length of the lenses of an astronomical telescope are 50 cm and 5cm. The length of the telescope when the image is formed at the least distance of distinct vision is:

The R.L of water is 4/3.If ray travels 24cm in air in a given time t,the distance traveled by light in water in the same time t is

If Foucoult's method for determining the velocity of light in air, the distance between the concave mirror and the rotating mirror was 5 km. The speed of rotation of the rotating mirror was 300 revolutions per second. If the reflected ray is displaced through π/60 radian, the velocity of light in air is :

The two lenses of an achromatic doublet should have

Electrons ejected from the surface of a metal, when light of certain frequency is incident on it, are stopped fully by a retarding potential of 3 volts. Photoelectric effect in this metallic surface begins at a frequency 6 x 1014s-1. The frequency of the incident light in s-1is : [ Planck's constant = 6.4 x 10-34Js, charge on the electron = 1.6 x 10-19C]

If the angle of a prism is 600 and angle of minimum deviations is 400, then the angle of refraction in the prism will be

Match the appropriate pairs from Lists I and II: List-I List-II 1.NItrogen molecules A.continuous spectrum 2.Incandescent solids B.Absorption spectrum 3.Fraunhoffer lines C.Band spectrum 4.Electric arc between iron rods D.Emission spectrum

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