Popular Electricity And Magnetism Questions

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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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. ...

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 ...

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 ...

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) ...

An unknown cell balances 300 cm of wire in a potentiometer circuit, but the balance length reduces to 280 cm when a resistance of 28 ohm is added in parallel with the cell.A standard cell of emf 1.1V balances 220 cm on the sa ...

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a thin half ring of radius R=20cm is uniformly charged with total charge q=0.70nC. find the magnitude of the electric field strength at the carvature centre of the half ring. ...

Q) One end of a horizontal thick wire of length 2L and radius 2R is welded to an end of another horizontal thin copper wire of length L and radius R.When the arrangement is stretched by applying forces at two ends, the ratio ...

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*Image* What's the difference between (c) and (d)? ...

A charged drop of oil of radius 2.76μm and density 920kg/m3 is held stationary in a vertically downward electric field of 1.65*106N/C.(i).Find the magnitude and sign of the charge on the drop.(ii) If the drop captures two el ...

Four point charges each of +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 T.The system of charges and the planar film are in equilibrium and a=k[q2/T] ...

*Image* Ans) is -12 v/m bt it shld be 12 v/m na...?? ...

A square loop of side length ' a ' , mass ' m ' and Resistance ' R ' enters a uniform magnetic field (B=B0 (-k)) with velocity ' v° ' at t = 0 sec Plot the variation of ' v ' with the distance from O ( Assume that ' v ' is e ...

*Image* A line of charge L=10^-6C/m is fixed on the rim of a wheel of radius R=1m,which is then suspended horizontally,so that it is free to rotate(the spokes are made of wood).In the central region up to radius a=1/2m,there ...

A non conducting ring of mass m and radius R has a charge Q distributed over its circumference.It is placed on a rough horizontal surface such that the plane of the ring is parallel to surface.A vertical mag. field B=B0t2is s ...

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A disc of mass m ,radius R is shown rolling on horz surface(having sufficient friction). Variation of electric fields with direction exist along its path as shown in figure *Image* 1.Find the velocity after very long time. 2. ...

In the circuit shown, calculate: a. p.d. between B and D b. current in the galvanometer c. effective resistance across the points A and C *Image* ...

*Image* Find the foce of attraction between the 2 charges??????? ...

A metallic ball is suspended by an insulated string, in an uniform electric field. A X-Ray of high radiation is passed through the ball in the field. What will happen to the ball? ...

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When an uncharged CONDUCTING ball of radius R is placed in a uniform electric field, surface charge density σ=σ°cosθ is induced on ball's surface where σ° is a constant What is the magnitude of resultant ELECTRIC FORCE ...

Capacitor C is charged to a potential V and the battery is disconnected. now if the plates are brought close slowly by some distance: a) some +ve work is done by external agent b) energy of capacitor will decrease c) energy o ...

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