Question 1 :
The class of diffraction in which incident and diffracted wave fronts are planar is called:<br/>
Question 2 :
Assertion: To increase resolving power of a telescope, the aperture ($a$) of the objective should be large.
Reason: Resolving power of the telescope is given by $\dfrac{2a}{1.22 \lambda}$
Question 3 :
Atwhat angle of incidence will the light reflected from glass $( \mu \, = \, 1.5)$ becompletely polarised
Question 4 :
In young's double slit experiment, the ratio of intensities of bright and dark bands is 16 which means:
Question 5 :
Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25cm, the minimum separation between two objects that human eye can resolve at 500 nm wavelength is :
Question 6 :
The diameter of the objective lens of microscope makes an angle $'\beta\ '$ at the focus of the microscope. Further, the medium between the object and the lens is an oil of refractive index 'n'. Then the resolving power of the microscope.
Question 10 :
A convex lens is in contact with a concave lens.The magnitude of the ratio of their focal length is 2:3. Their equivalent focal length is 30 cm. Their individual focal lengths are (in cms)
Question 11 :
A mark is made on the surface of a glass sphere of diameter $10 cm$ and refractive index $1.5$. It is viewed through the glass from a portion directly opposite. The distance of the image of the mark from the center of the sphere will be
Question 12 :
The objective and eyepiece of an astronomical telescope are doubled convex lenses with refractive index $1.5$. When the telescope is adjusted to infinity, the separation between the two lenses is $16\ cm$. If the space between the lenses is now filled with water and again telescope is adjusted for infinity, then the present separation between the lenses is:
Question 13 :
A man is looking at a small object placed at his near point. Without altering the position of his eye or the object, he puts a simple microscope of magnifying power  $5\mathrm { X }$  before his eyes. The angular magnification achieved is?
Question 14 :
The wavelength associated with an electron having kinetic energy is given by the expression:<br/>
Question 15 :
For photoelectric emission from certain metal, the cutoff frequency is.  If radiation of frequency 2 impinges on the metal plate, the maximum possible velocity of the emitted electron will be (m is the electron mass) -
Question 16 :
According to Corpuscular theory, the color of the light is given by :<br/>
Question 17 :
An oil drop of mass 'm' falls through a viscous medium. The viscous drag force (F) is proportional to the velocity of the drop. At the instant it begins to fall, the net force that acts on the oil drop is<br/>
Question 18 :
Find the de-Broglie wavelength of an electron with kinetic energy of $120\ eV$.
Question 19 :
A particle moving with kinetic energy E has de Broglie wavelength $\lambda$. If energy $\Delta E$ is added to its energy, the wavelength become $\lambda /2$. Value of $\Delta E$, is?
Question 20 :
On the basis of the uncertainty principle it can be proved that
Question 21 :
What is the purpose of filament in electron gun inside a cathode ray tube?
Question 22 :
According to Rutherford's  $\alpha$-scattering experiment, which of the following statement is true?<br/>
Question 23 :
A proton, a deuteron and an $\alpha$-particle accelerated through the same potential difference enter a region of uniform magnetic field, moving at right angles to $B$. What is the ratio of their kinetic energies?
Question 24 :
How will you relate velocity of cathode rays to c, if ‘c' denotes the velocity of light?<br/>
Question 25 :
An electron at rest is accelerated through a potential difference of 200 V. If the electron acquires a velocity $8.4 \times 10^6 m/s$, the value of e/m of electron is
Question 26 :
According to Rutherford's $\alpha$-scattering experiment, which of the following is the INCORRECT conclusion? <br/>
Question 27 :
Whatshould retarding potential differencebe applied between electrodes of the photocell for the photocurrent to drop to zero?
Question 28 :
What will be the velocity of the electron when it just reaches the positive plate?<br>
