Correct option is (A) $\frac{3 \mathrm{v}}{2}$ $\begin{array}{l} \mathrm{hv}=\mathrm{W}+\frac{\mathrm{v}_{0}}{2} \mathrm{e} \\ \frac{\mathrm{h} v}{2}=\mathrm{W}+\mathrm{v}_{0} \mathrm{e}...
When a certain photosensitive surface is illuminated with monochromatic light of frequency v, the stopping potential for the photocurrent is 
When the surface is illuminated by monochromatic light of frequency 
, the stopping potential is 
. the threshold frequency for photoelectric emission is:
(A) 
(B) 
(C) 
(D) 
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. Unknown resistance ‘ 
‘ is connected in left gap and 
in right gap, null point divides the wire in the ratio 
. Find the current drawn from the battery of 
having negligible resistance.
permeability of vacuum, 
magnetic susceptibility)
having equal charges after being accelerated through same potential difference enter a region of uniform magnetic field and describe a circular paths of radii ‘ 
‘ and ‘ 
‘ respectively. The ratio of the mass of 
to that of 
is
![\left[\frac{\mathrm{r}_{2}}{\mathrm{r}_{1}}\right]^{2}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-8576e94466b638e76d49f6a15d3e2940_l3.png "Rendered by QuickLaTeX.com")
![\left[\frac{\mathrm{r}_{1}}{\mathrm{r}_{2}}\right]^{2}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-508e81114cccf8287500c32565603618_l3.png "Rendered by QuickLaTeX.com")
‘ is incident on photosensitive surface, the stopping potential is ‘ 
‘. When light of wavelength ‘ 
‘ is incident on same surface, the stopping potential is 
. Threshold wavelength for the surface is
It reduces to 
of its Loriginal value in ‘t’ second. If the e.m.f. induced is 
then ‘t’ in second is
is ‘ 
‘. The work done in increasing it from 
will be
bright band and 
bright band. Wavelength of light used is 
. The path difference between PA and QA is
is connected to a battery of emf 
with 
resistance in series. A full scale deflection of 20 divisions is obtained in the galvanometer. To reduce the deflection to 10 divisions, the resistance in series required is
‘, then potential difference of the other capacitor will become
‘ to lower orbit, ‘p’. The wavelength will be minimum for the transition
to 
to 
to 
to 
maximum electron density of ionosphere, 
acceleration due to gravity)
. The angle of deviation is
equal to 
voltage gain without feedback, 
feedback factor )
and the separation between the plates is ‘ 
‘, ‘ 
‘ and ‘ 3 d’ respectively. The equivalent capacity of combination is 
absolute permittivity of free space)
at point 
and 
at point 
on the screen. The difference between the resultant intensities at point 
‘ has de-Broglie wavelength ‘ 
When proton of mass ‘ 
‘, is accelerated through potential difference ‘ 
‘, the de-Broglie wavelength associated with it will be (Assume that wavelength is determined at low voltage)
B) 
ampere flows through the primary coil of the transformer. The coefficient of mutual inductance between primary and secondary coil is 1 henry. The peak e.m.f. induced in secondary coil is (Frequency of a.c. 
)
. The magnetic flux through the rod is 
and its cross-sectional area is 
. The magnetic permeability of the rod in 
is
long. If the length of the potentiometer wire is increased without changing the cell, the balancing length will (Driving source is not changed)
‘ at a height ‘h’ above the earth’s surface is 
then 
radius of earth)
‘ has maximum angular displacement ‘ 
‘. The maximum kinetic energy of the bob of mass ‘ 
‘ be the length of a thin uniform rod. In first case, axis of rotation is passing through centre and perpendicular to the length of the rod. In second case axis of rotation is passing through one end and perpendicular to the length of the rod. The ratio of radius of gyration in first case to second case is
‘ is spread into 512 droplets of same size. The final surface energy of the droplets is
. If length and breadth are reduced to 
rd of initial value and temperature is raised to 
then energy emitted per second becomes
‘ are separated by a distance ‘ 
‘. At a point on the line joining them the gravitational field is zero. The gravitational potential at that point is (G = Universal constant of gravitation)
. On this wave, how far away are the two points having phase difference of 
?
then the inner radius of that pipe will be
‘. Then the sag of bending of beam is ( 
Young’s modulus of material of steel)
‘ and thickness 
has moment of inertia ‘I’ about an axis passing through its centre and perpendicular to its plane. Disc is melted and recast into a solid sphere. The moment of inertia of a sphere about its diameter is
than second overtone of open pipe. The fundamental frequency of open end pipe will be A) 
B) 
D) 
‘ 
is inserted symmetrically and one end of the combination is dipped vertically in water such that the lower end of the combination is at same level. The rise of water in the capillary tube is 
surface tension of water, 
density of water, ![]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-478d84af1027ee3593251b323a3fb181_l3.png "Rendered by QuickLaTeX.com")
‘ in air and with period ‘ 
, in water. Relation between ‘ 
, density of water 
)
and 
of same material are stretched by same tension. The radius of the string A is double the radius of string B. Transverse wave travels on string A with speed ‘ 
‘ and on string 
with speed ‘ 
‘. The ratio 
is
‘ at the end of second revolution, after the revolution has started then the tangential acceleration is
‘ connected to a horizontal spring performs S.H.M. with amplitude ‘
‘. While mass ‘ 
‘ is placed on it so that both the masses move together with amplitude 
, The ratio of 
is 
![\left[\frac{m_{1}}{m_{1}+m_{2}}\right]^{\frac{1}{2}}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-2b29b57ed39eb1f6c58436a799bc7bae_l3.png "Rendered by QuickLaTeX.com")
![\left[\frac{\mathrm{m}_{1}+\mathrm{m}_{2}}{\mathrm{~m}_{1}}\right]^{\frac{1}{2}}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-f41789fa421a8e3dd967c1a79e94c1ec_l3.png "Rendered by QuickLaTeX.com")
![\left[\frac{m_{2}}{m_{1}+m_{2}}\right]^{\frac{1}{2}}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-e261477e0e770b6b424c21c834fa7358_l3.png "Rendered by QuickLaTeX.com")
![\left[\frac{\mathrm{m}_{1}+\mathrm{m}_{2}}{\mathrm{~m}_{2}}\right]^{\frac{1}{2}}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-17db4e934120c4864100c1c60fc53b04_l3.png "Rendered by QuickLaTeX.com")
![[\frac{1}{3}]^{rd}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-9f96177eb515481513c54e551e5e8124_l3.png "Rendered by QuickLaTeX.com")
kinetic energy per unit volume of a gas![[\frac{2}{3}]^{rd}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-496e049a5aa2709ddb63a237a5e8e0be_l3.png "Rendered by QuickLaTeX.com")
kinetic energy per unit volume of a gas![[\frac{3}{4}]^{th}](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-152c9f0a76e8d19379623b976244d69f_l3.png "Rendered by QuickLaTeX.com")
kinetic energy per unit volume of a gas
kinetic energy per unit volume of a gas
’, the apparent frequency of emitted note is ‘
’. When the observer moves away from the source with velocity ‘
’. If ‘
’ is the velocity of sound in air and 
then 
where ‘R’ is the universal gas constant and ‘
’ is molar specific heat at constant volume. The gas is made up of molecules which are