Frequency of the incident photon is provided as $v=488 \mathrm{~nm}=488 \times 10^{-9} \mathrm{~m}$ Maximum speed of the electrons is $\mathbf{v}=\mathbf{6 . 0} \times \mathbf{1 0}^{5} \mathrm{~m} /...
Light of frequency 
is incident in a metal surface. Electrons with a maximum speed of 
are ejected from the surface. What is the threshold frequency for photoemission of electrons?
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Will this metal give photoelectric emission for incident radiation of wavelength 330 nm?
. If the light of frequency 
is incident on the metal, predict the cut-off voltage for the photoelectric emission.
sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength
(a) What is the energy per photon associated with the sodium light? (b) At what rate are the photons delivered to the sphere?
Calculate the value of Planck’s constant.
. How many photons are incident on the Earth per second/square meter? Assume an average wavelength of 
so that it just suffers total internal reflection at the other face? The refractive index of the material of the prism is 1.524.
is produced by a helium-neon laser. The power emitted is 
. How fast does a hydrogen atom have to travel in order to have the same momentum as that of the photon?
What is the maximum kinetic energy of photoelectrons emitted?
When light of frequency 
is incident on the metal surface, photoemission of electrons occurs. What is the maximum speed of the emitted photoelectrons?
electrons.
and the metre shows full-scale deflection for a current of 4 mA. How will you convert the metre into an ammeter of range 0 to 6 A?
and the metre shows full scale deflection for a current of 3 mA. How will you convert the metre into a voltmeter of range 0 to 18 V?
long and of radius, 
has 3 layers of windings of 300 turns each. A 
long wire of mass 
lies inside the solenoid (near its centre) normal to its axis; both the wire and the axis of the solenoid are in the horizontal plane. The wire is connected through two leads parallel to the axis of the solenoid to an external battery which supplies a current of 
in the wire. What value of current (with an appropriate sense of circulation) in the windings of the solenoid can support the weight of the wire? 
.
is placed in a uniform magnetic field of 
normal to the plane of the coil. If the current in the coil is 
, what is the average force on each electron in the coil due to the magnetic field? (The coil is made of copper wire of cross-sectional area 
, and the free electron density in copper is given to be about 
is established along the positive z-direction. A rectangular loop of sides 
carries a current of 
What is the torque on the loop in the different cases shown in the figure? What is the force on each case? Which case corresponds to stable equilibrium?
with respect to the surface of the earth, corresponding to an electric field that decreases with altitude. Near the surface of the earth, the field is about 
. Why then do we not get an electric shock as we step out of our house into the open? (Assume the house to be a steel cage so there is no field inside!)
Will he get an electric shock if he touches the metal sheet the next morning? 
Due to the slight conductivity of the atmosphere up to about 
(beyond which it is good conductor), about + 
is pumped every second into the earth as a whole. The earth, however, does not get discharged since thunderstorms and lightning occurring continually all over the globe pump an equal amount of negative charge on the earth.)
and charge 
is enclosed by a spherical shell of radius 
and charge 
. Show that if 
, using a material of dielectric constant 3 and dielectric strength of about 
. (Dielectric strength is the maximum electric field a material can tolerate without breakdown, i.e., without starting to conduct electricity through partial ionisation.) For safety, we should like the field never to exceed, say 
of the dielectric strength. What minimum area of the plates is required to have a capacitance of 
?
and radii 
and 
. The outer cylinder is earthed and the inner cylinder is given a charge of 
. Determine the capacitance of the system and the potential of the inner cylinder. Neglect end effects (i.e., bending of field lines at the ends).
and 
are brought close to each other. Is the magnitude of the electrostatic force between them exactly given by 
, where 
is the distance between their centres? 
dependence (instead of 
, would Gauss’s law be still true? 
than say, mica 
.
and an outer sphere of radius 
. The outer sphere is earthed and the inner sphere is given a charge of 
. The space between the concentric spheres is filled with a liquid of dielectric constant 
where 
is the charge on the capacitor, and 
is the magnitude of the electric field between the plates. Explain the origin of the factor 
.
capacitor is charged by a 
supply. It is then disconnected from the supply and is connected to another uncharged 
capacitors. How much electrostatic energy of the first capacitor is lost in the form of heat and electromagnetic radiation?
each and are separated by 
. The capacitor is charged by connecting it to a 
supply. 
and the magnitude of electric field 
? [You will realise from your answer why ordinary capacitors are in the range of 
or less. However, electrolytic capacitors do have a much larger capacitance 
F) because of the very minute separation between the conductors.]
in a circuit across a potential difference of 
capacitor are available to him each of which can withstand a potential difference of not more than 
Suggest a possible arrangement that requires the minimum number of capacitors.
, and contrast your results with that due to an electric dipole, and an electric monopole (i.e., a single charge).
and 
are located at points 
and 
, respectively. 
and 
. 
to 
along the 
-axis? Does the answer change if the path of the test charge between the same points is not along the 
are connected to each other by a wire. What is the ratio of electric fields at the surfaces of the two spheres? Use the result obtained to explain why the charge density on the sharp and pointed ends of a conductor is higher than on its flatter portions.
molecule is removed, we get a hydrogen molecular ion 
, and the electron is roughly 
from each proton. Determine the potential energy of the system. Specify your choice of the zero of potential energy.
A:
separation?
is surrounded by a hollow co-axial conducting cylinder. What is the electric field in the space between the two cylinders?![\[\left(E_{2}-E_{1}\right) \cdot \hat{n}=\frac{\sigma}{\epsilon_{0}}\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-54db8c7b760751ea8adfd4d811d7f57f_l3.png "Rendered by QuickLaTeX.com")
is a unit vector normal to the surface at a point and 
is the surface charge density at that point. (The direction of 
. 
and outer radius 
has a charge 
is placed at the center of the shell. What is the surface charge density on the inner and outer surfaces of the shell? 
and outer radius 
has a charge 
and 
apart. Find the potential and electric field: (a) at the mid-point of the line joining the two charges, and 
is located at the origin. Calculate the work done in taking a small charge of 
from a point 
to a point 
, via a point 
).
supply. It is then disconnected from the supply and is connected to another uncharged 600 pF capacitor. How much electrostatic energy is lost in the process?
, a 3 mm thick mica sheet (of dielectric constant = 6) were inserted between the plates, 
and the distance between the plates is 
Calculate the capacitance of the capacitor. If this capacitor is connected to a 
supply, what is the charge on each plate of the capacitor?
and 
are connected in parallel. 
What will be the capacitance if the distance between the plates is reduced by half and the space between them is filled with a substance of dielectric constant 
distributed uniformly on its surface. What is the electric field 
from the centre of sphere.
and 
are placed at points 
and 
apart. (1) Identify the equipotential surface of the system. 
at each of its vertices. Calculate the potential at the centre of the hexagon.![\[{}_{94}^{239}Pu\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-20a0ebf3997617e55dafd1d868016d35_l3.png "Rendered by QuickLaTeX.com")
![\[{}_{92}^{235}U\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-921d2d0179581f658ce400d742db4752_l3.png "Rendered by QuickLaTeX.com")
and 
are located 
apart from each other. At what point (s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.![\[{}_{10}^{23}Ne\]](https://www.learnatnoon.com/s/wp-content/ql-cache/quicklatex.com-e29ca3a0219f614cc29b3bae3e497cfb_l3.png "Rendered by QuickLaTeX.com")
exists in a cylindrical region of a radius of 
, its direction parallel to the axis along east to west. A wire carrying a current of 
A in the north to south direction passes through this region. What is the magnitude and direction of the force on the wire if, (a) the wire intersects the axis, (b) the wire is turned from N-S to the northeast-northwest direction
(for a short time). What is the force per unit length between the wires if they are 
long and