Hot questions

0 votes

0 answers

A long straight wire carrying current of 25A rests on a table as shown in Fig. Another wire PQ of length 1m, mass 2.5 g carries the same current but in the opposite direction. The wire PQ is free to slide up and down. To what height will PQ rise?

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Electric Field LinesAn electric field line in general is a curve drawn in such a way that the tangent to it at each point is in the direction of the electric field at that point. A field line is a space curve, i.e. a curve in three dimensions. Electric field lines are thus used to pictorially map the electric field around a charge or a configuration of charges.The density of field lines is more near the charge. Away from the charge, the field is weak, so the density of field lines is less.Electric field lines always move

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

A card sheet divided into squares each of size 1 mm2 is being viewed at a distance of 9 cm through a magnifying glass (a converging lens of focal length 9 cm) held close to the eye. What is the magnification produced by the lens? How much is the

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

A tank is filled with water to a height of 12.4 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 9.3 cm. What is the refractive index of water? If water is replaced by a liquid of refractive index 1 .6 up to the same height, by what distance would the microscope have to be moved to focus on the needle

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

The photoelectric cut-off voltage in a certain experiment is 1.5 V. What is the maximum kinetic energy of photoelectrons

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

For a given K.E. which of the following has the smallest de–broglie wavelength: electron, proton, α − particle

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Define the term dipole moment `vecP` of an electric dipole indicating its direction. Write its S.I unit. An electric dipole is placed in a uniform electric field `vecE` . Deduce the expression for the Torque acting on

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

What is the acceleration of the small ball at the instant of releasing the rod? A thin homogeneous rod of mass m and length `l` is free to rotate in vertical plane about a horizontal axle pivoted at one end of the rod. A small ball of mass m and charge q is attached to the opposite end of this rod. The whole system is positioned in a constant horizontal electric field of magnitude mg `E=(mg)/(2q)`. The rod is released from shown position from

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Consider the charges q, q, and –q placed at the vertices of an equilateral triangle, as shown in Fig. . What is the force on each

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

A wire of length 2m is moving at a speed `2ms^(-1)` keep its length perpendicular to uniform magnetic field of 0.5 T. The resistance of circuit joined with this wire is `6Omega`. The rate at which wolrk is being done to keep the wire moving at constant speed is

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

A length L of wire carries a steady current 1. It is bent first to form a coil of 1 turn. The same length is now bent more sharply to give a double loop of smaller radius. The magnetic field at the centre caused by the same current

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

If charges move without collisions through the conductor, their kinetic energy would also change, so that the total energy

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Two bulbs of `40W and 60W` are connected to `220V` line, the ratio of resistance will

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Faraday’s Laws According to the Faraday’s first law, whenever the amount of magnetic flux linked with a circuit changes, an emf is induced in it. Induced current is determined by the rate at which the magnetic flux changes.Mathematically, the magnitude of the induced emf in a circuit is equal to the rate of change of magnetic flux through the circuit.Induced emf `prop` Rate of change of magnetic fluxWire loop is rotated in a magnetic field. The frequency of change of direction of the induced emf

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

What is the Fresnel's distance? For what distance is ray optics a good approximation when the aperture is 3 mm wide and the wavelength is 500

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

In a single slit diffraction experiment, a monochromatic source of light of wavelength `lambda` illuminates a narrow slit of width `a.` Show giving appropriate reasoning, that the half angular width of the central maximum in the observed pattern is (nearly) equal to

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

If the above experiment is repeated of interference, by replacing two sources to a single slits of width 1mm. What would be the thickness of central

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Ultraviolet light of wavelength 2271 Å from a 100 W mercury source irradiates a photo-cell made of molybdenum metal. If the stopping potential is –1.3 V, estimate the work function of the metal. How would the photo-cell respond to a high intensity (∼105 W m–2) red light of wavelength 6328 Å produced by a He-Ne laser

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

0 votes

0 answers

Which of the following functions of time represent (a) simple harmonic, (b) periodic but not simple harmonic, and (c) non-periodic motion? Give period for each case of periodic motion (ω is any positive constant):

asked Mar 20, 2022 in 11th Physics by varun (6.7k points)

0 votes

0 answers

A hemisphere is uniformely charged positively. The electric field at a point on a diameter away from the centre is

asked Mar 20, 2022 in 12th Physics by varun (6.7k points)

Hot questions

Categories