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If `100 J` of work has to be done in moving an electric charge of `4C` from a place, where potential is `- 10V` to another place where potential is `V` volt, find the value of

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Equipotential SurfaceIn physics, the region in space where every point in it is at the same potential, is called equipotential or isopotential. An equipotential region of a scalar potential in three-dimensional space is often an equipotential surface, but it can also be a three-dimensional region in space. The gradient of the scalar potential is everywhere perpendicular to the equipotential surface, and zero inside a three-dimensional equipotential region. In case of electrical conductors, if a and b are any two points within or at the surface of a given conductor, and given there is no flow of charge being exchanged between

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The electrical conductivity of the metal decreases with temperature,

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Magnetic Field of a SolenoidMohan tightly wound a very long copper wire on a PVC pipe and carefully took the pipe out. The two ends of the copper wire then attached to a battery. This cylindrical shape of copper wire showed few properties of a bar magnet. Later he found that it is called a solenoid and this solenoid is used in several devices such as door bell, relay switch etc. The magnetic field of a solenoid is given below.The magnetic field strength of a solenoid having n turns is `B=mu_0nl`, where, `I` is the current flowing in the solenoid.An

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The flux linked with a circuit is given by `phiB = t^2 +2`. The graph between time (X-axis) and induced emf (Y-axis) will be

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Eddy CurrentCoil is wound over metallic core is helpful in reducing eddy currents in the metallic cores of transformers, electric motors, induction furnaces and other such devices (as shown below). Eddy currents are undesirable since they heat up the core and dissipate electrical energy in the form of heat. These currents are minimised by using laminations of metal to make a metal core. The plane of the laminations must be arranged parallel to the magnetic field, so that

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Same current is flowing in two alternating circuits. The first circuit contains only inductance and the other contains only a capacitor. If the frequency of the emf of AC is increased, the effect on the value of the

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Double-convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of the same radius of curvature. What is the radius of curvature required if the focal length is to be

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A beam of light converges at a point P. Now a lens is placed in the path of the convergent beam 12cm from P. At what point does the beam converge if the lens is a concave lens of focal length

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What is the focal length of a convex lens of focal length 30cm in contact with a concave lens of focal length 20cm? Is the system a converging or a diverging lens? Ignore thickness of the

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Use the mirror equation to show that on object placed between F and 2F of a concave mirror produces a real image beyond 2

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A convex lens made up of a glass of refractive index 1.5 is dipped in turn in (i) a medium of refractive index 1.65 (ii) a medium of refractive index 1.33 (a) Will it behave as a converging lens or a diverging lens in the two cases? (b) How will its focal length change in the two

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Use the mirror equation to show that (i) An object placed between `f` and `2f` of a concave mirror produces a real image beyond `2f`. (ii) A convex mirror always produces a virtual image independent of the location of the object. (iii) An object placed between the pole and focus of a concave mirror produces a virtual and enlarged

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State the necessary conditions for producing total internal reflection of light. Draw ray diagrams to show how specially designed prisms make use of total internal reflection to obtain inverted image of the object by deviation of rays (i) through 90° and (ii) through

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Monochromatic light of wavelength 589 nm is incident from air on a water surface. What are the wavelength, frequency and speed of reflected, Refractive index of water is

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In a Young's double slit experiment, (i) deduce the conditions for constructive and destructive interference. Hence, write the expression for the distance between two consecutive bright or dark fringe. (ii) what change in the interference pattern do you observe, if the two slits, `S_1 and S_2` are taken as point sources? (iii) plot a graph of the intensity distribution versus path difference in this experiment. Compare this with the intensity distribution of fringes due to diffraction at a single slit. What important difference do you

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The human eye has an approximate angular resolution of `φ = 5.8 × 10^(-4)` rad and a typical photoprinter prints a minimum of 300 dpi (dots per inch, 1 inch = 2.54 cm). At what minimal distance z should a printed page be held so that one does not see the individual

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The work function of caesium metal is 2.14 eV. When light of frequency 6 ×1014Hz is incident on the metal surface, photoemission of electrons occurs. What is the(i) maximum kinetic energy of the emitted electrons,(ii) Stopping potential,(iii) maximum speed of the emitted

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In an experiment on photoelectric effect, the slope of the cut-off voltage versus frequency of incident light is found to be 4.12 × 10–15 V s. Calculate the value of Planck’s

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An electron and a photon each have a wavelength of 1.00 nm. Find the kinetic energy of

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