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What happen when flannel is rubbed over a glass rod?

Important Questions on Electrostatics

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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging

As shown in the figure, two particles, each of mass 'm' tied at the ends of a light string of length 2a are kept on a frictionless horizontal surface. When the mid point (P) of the string is pulled vertically upwards with a small but constant force F, the particles move towards each other on the surface. Magnitude of acceleration of each particle, when the separation between them becomes 2x is

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A neutral spherical copper particle has a radius of 10 nm1 nm=10-9 m. It gets charged by applying the voltage slowly adding one electron at a time. Then, the graph of the total charge on the particle versus the applied voltage would look like
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Two identical conducting spheres A and B carry equal charge. They are initially separated by a distance much larger than their diameters and the force between them is F. A third identical conducting sphere C is uncharged. Sphere C is first touched to A, then to C and removed. As a result, the force between A and B now is
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
The attractive force results when a glass rod rubbed with a silk and a plastic rod rubbed with a fur brings together. During friction which type of charges are developed on glass rod and plastic rod? 
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Two isolated conducting spheres S1 and S2 of radius 23R and 13R have 12 μC and -3 μC charges, respectively, and are at a large distance from each other, They are now connected by a conducting wire. A long time after this is done the charges on S1 and S2 are respectively:
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Two insulated charged spheres of radii 20 cm and 25 cm, respectively, and having an equal charge Q are connected by a copper wire. Then, they are separated. Which of the following is correct ?
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A neutral metallic sphere is placed near a negative point charge (outside the sphere). The net charge on sphere, then 


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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
In a system used for spraying cars, a car body is positively charged. Neutral droplets of paint are then attracted to the car because the positive car body induces a charge on the droplets of paint. Which diagram best shows the charge pattern?
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
A comb runs through one's dry hair attracts small bits of paper. This is due to
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Which of the following cannot be charged easily by friction?
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Suppose there are two copper spheres A and B having identical sizes. The distance between the centers of sphere is 50 cm and the charge on each sphere is 6.5×10-7 C. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B?
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
In a system used for spraying cars, a car body is positively charged. Neutral droplets of paint are then attracted to the car because the positive car body induces charge on the droplets of paint. Which diagram best shows the charge pattern?
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Which of the following diagram is correct ?
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The diagram shows an earthed conducting sphere held close to a positively charged dome.




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What is the charge and potential of the conducting sphere?
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A table tennis ball, covered with conducting paint, is suspended by a silk thread so that it hang between two plates. Out of these, one is earthed and other is connected to a high voltage generator. This ball,
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The energy spectrum of a black body exhibits a maximum around a wavelength λ0. The temperature of the black body is now changed such that the energy is maximum around a wavelength 3λ04 . The power radiated by the black body will now increase by a factor of
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Five Styrofoam balls are suspended from insulating threads. Several experiments are performed on the balls and the following observations are made -

(i) Ball A repels C and attracts B

(ii) Ball D attracts B and has no effect on E

(iii) A negatively charged rod attracts both A and E.

An electrically neutral Styrofoam ball gets attracted if placed nearby a charged body due to induced charge. What are the charges, if any, on each ball


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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
Assertion: If there exists coulomb attraction between two bodies both of them may not be charged.

Reason: In coulomb attraction two bodies are oppositely charged.
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Two identical metal spheres A and B are supported on insulating stands and are placed in contact. What kind of charges will A and B develop when a negatively charged ebonite rod is brought near A?
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Physics>Electricity and Magnetism>Electrostatics>Methods of Charging
A cylindrical conductor is placed near another positively charged conductor. The net charge acquired by the cylindrical conductor will be