Frequent Electricity And Magnetism Questions

A parallel plate capacitor of area 60cm^2 and separation 3mm is charged initially at 90 micro coulomb. If the medium between the plates get slightly conducting and the plate loses charge initially at the rate of 2.5 *10^-8 C ...

infinite number of straight wires each carrying current i are equally placed as shown in the fig. adjacent wires have curent in opposite direction. net magnetic field at point p is *Image* a. μi ln2/4π 3 a k b. μi ln4/4π ...

1.Determine the magnetic field at the centre of the current carrying wire arrangement shown in the figure. the arrangement extends to infinity. the wires joining the successive squares are along the line passing through the c ...

What is the magnitude of magnetic field at centre O of loop of radius √2 m made of uniform wire when a current of 1 A enters in the loop and taken out of it by two long wire as shown ...

A disk of radius r,mass m which has a charge q distributed uniformly over it is rotating in a magnetic field B about it's axis with an angular speed ω.Find the ratio of magnetic moment and angular momentum. ...

A coil of area A = 0.5 m2 is situated in a uniform magnetic field B = 4.0 wb/m2 and area vector makes an angle of 60o with respect to the magnetic field as shown in figure. The value of the magnetic flux through the area A wo ...

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A circular loop of radius R carries a current I.Another circular loop of radius r(<<R) carries a current i and is placed at the centre of the larger loop.The planes of the two circles are at right angle to each other.Fi ...

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The magnetic field existing in a region is given by B=B0(1+x/l)k→.A square loop of edge l and carrying a current i,is placed with it's edges parallel to the x-y axes.Find the magnitude of the net magnetic force experienced ...

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in order to increase the resistance of a given wire of uniform cross section to 4 times it's value, a fraction of it's length is stretched uniformly till the full length of the wire becomes 3/2 times the original length.what ...

Copper has 1 conduction electron per atom.its density is 8.89 g/cc and its atomic wt is 63.54 g/mol. If a copper wire of diameter 1 mm carries a current of 2 A. What is drift velocity in the wire. ...

a battrry of emf 10V and internal resistance 0.5 ohms is connected across a variable resistance R. What is the value of R for which the power delivered in it is maximum? ...

What is the meaning of μμC? ...

two conducting spheres of radii r1 and r2 have charge q1 and q2 respectively.after bringing them in contact,what happens to the energy of the system? a)no change b)increase if q1r2≠q2r1 c)decrease always d)decrease if q1r2â ...

A parallel plate capacitor of capacitance C is connected to a battery and is charged to a potential difference V. Another capacitor of capacitance 2C is similarly charged to a potential difference 2V. The charging battery is ...

Four point charges each of charge +q are rigidly fixed at the four corners of a square planar soap film of side a.The surface tension of the soap film is S.the system of charges and planar film are in equilibrium.Then find a ...

How to find the potentials at points A,B,C,D,E,F. *Image* ...

{Shastras Q-21} a point charge q is brought from infinity and is placed at the center of a conducting neutral spherical shell of inner radius 'a' and outer radius 'b', then work done by external agent is. A}0 B}kq2/2b C}kq2/2 ...

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TWO CONDUCTING plates each of area A are separated by distance d and they are parallel to each other. A conducting medium of varying conductivity fills space between them. the conductivity varies linearly σ to 2σ as we move ...

Condenser A has a capacity of 15 when it is filled with a medium of dielectric constant 15. Another condenser B has a capacity 1 with air between the plates. Both are charged separately by a battery of 100V. After charging, b ...

A bulb is made using two filaments. A switch selects whether the filaments are used individually or in parallel. When used with a 15 V battery, the bulb can be operated at 5 W, 10 W or 15 W. What should be the resistances of ...

why does potential drop across a capacitor????? ...

An electric dipole is placed in an electric field generated by a point charge a) The net electric force on the dipole must be zero b) The net electric force on the dipole may be zero c) The torque on the dipole due to the fie ...

The capacity of a parallel plate condenser is . If a dielectric of relative permitivity and thickness equal to one fourth the plate separation is placed between the plates, then its capacity becomes C. The value of will be a) ...

Determine the capacitance of a system consisting of a metal ball of radius a and an infinite conducting plane separated from the centre of the ball by the distance b if b>>a. ...

A sphere of 4 cm radius is suspended within a hollow sphere of 6 cm radius. The inner sphere is charged to a potential 3 e.s.u. When the outer sphere is earthed. The charge on the inner sphere is a) 54 e.s.u. b) frac{1}{4}, e ...