Electrification

Q.

When a plastic comb is rubbed with hair, it acquires some charges due to which it attracts tiny pieces of paper. The type of charge, which the comb acquires from the hair is ___.

1. Positive

2. Negative

3. alpha

4. beta

Q.

When we remove polyester or woollen clothes in dark, we can see a spark and hear a crackling sound. Which of the following is responsible for it?

1. Static electricity

2. Convection

3. Potential difference

4. Radiation

Q. ​​​​​​Is current constituted by protons? If so then how come we say that current moves in the opposite direction to the direction of electrons when protons do no move from their position?

Q.

Do the following conduct electricity -

1.Glycerine

2.Hair Oil

Q.

When charges move, they constitute a/an:

1. electric current

2. pressure wave

3. heat wave

4. all of the above

Q.

How can you find the nature of charge on a body with the help of a gold-leaf electroscope?

Q.

Write the three ways to produce magnetic fields.

Q.

What is a Band Gap Chemistry?

Q.

A positive point charge is brought near to a neutral conductor, and then the conductor becomes negatively charged.

1. True
2. False

Q. In the process of electrostatic induction.

1. A conductor is rubbed with an insulator.
2. A Charge is produced by friction.
3. Negative and positive charges are separated.
4. Electrons are 'sprayed' on the object.

Q. Ques. A sphere shaped metallic body of radius 5cm gained 15×10^6 C electrons. Find the surface charge density of the sphere.

Q. When a body is charged by induction, then the body

1. becomes neutral
2. loses whole of the charge on it
3. does not lose any charge
4. loses part of the charge on it

Q. What do you mean by 'charging by conduction'? What kind of charge does the body acquire?

Q. Can conductors be charged by friction?

1. Yes
2. No
3. It is not possible to charge conductor at all
4. None of these

Q.

Two charges of unknown magnitudes are kept 5m away from each other. The magnitude of force between them is measured to be F. If these charges are then moved so that the distance between them is 20m, what is the new force between them?

1. F/16

2. F/4

3. F/8

4. F/20

Q.

The activity of removing the charge on a body is called ___

Q.

Two uniformly charged spheres with radii $r_1$ & $r_2$ and charges $Q_1$ & $Q_2$ are separated by distance d (from the periphery of the two spheres). What is the magnitude of force on $Q_2$ due to $Q_1$?

1. F=KQ₁Q₂/d²

2. F=KQ₁Q₂/(d+r₂)²

3. F=KQ₁Q₂/(d+r₁)²

4. F=KQ₁Q₂/(d+r₁+r₂)²

Q. A neutral metal sphere is touched to a negatively charged metal rod. As a result the sphere will be_____ and the metal rod will be ________ . Fill in the gaps

1. Positively charged
2. Negatively charged
3. None
4. Neutral

Q. What is known as charging by induction method?

1. charge created through contact of charged object and not by influence
2. charge created through influence of charged object and not by contact
3. charge not generated
4. None

Q. Two identical conducting balls having positive charges $q_1$ and $q_2$ are separated by a distance r. If they are made to touch each other and then separated to the same distance, the force between them will be

1. same as before
2. more than before
3. less than before
4. zero

Q. State whether given statement is correct.

The total charge present on an object is conserved when no friction or any other charged object is brought near it.
Justify.

Q. nn nt nttTWO IDENTICAL PARTICLES OF MASS M CARRYING A CHARGE Q EACH. INITIALLY ONE IS AT REST ON A SMOOTH HORIZONTAL PLANE AND THE OTHER IS PROJECTED ALONG THE PLANE DIRECTLY TOWARDS FIRST PARTICLE FROM A LARGE DISTANCE WITH SPEED V . THE CLOSEST DISTANCE OF APPROACH BE? nn ntn

Q.

Through which one of the given mediums can an electrical charge be easily transferred from a charged object to another?

1. vacuum

2. Air

3. insulator

4. conductor

Q. When a charged aluminum plate is touched to a neutral metal sphere then neutral metal sphere gets charged up. This happens due to which method of charging ?

1. Charging by conduction
2. Charging by friction
3. Charging by induction
4. None

Q.

Who proved that lightning is caused by the static electricity?

Q. Two uncharged spheres A and B are kept near to each other. A negatively charged rod is brought near one of the spheres. Identify the charge induces on the far right side of sphere B :

1. Positive
2. Uncharged
3. Negative
4. Equally positive and negative
5. Neutral

Q. The figure below shows an insulated wire. Which of the following condition is used to determine the shape of the magnetic field around the insulated wire?

1. Depend upon the strength of the magnetic field.
2. Depends upon the number of turns in the wire.
3. Depends upon the type of the wire.
4. Depends upon the shape of the wire.

Q.

The linear charge density of a thin metallic rod varies with the distance ${}^{\prime }{x}^{\prime }$ from one end as $\lambda ={\lambda }_0{x}^2\left(0⩽x⩽l\right).$ The total charge on the rod is:

1. $\frac{{\lambda }_0{l}^3}{3}$
2. $\frac{{\lambda }_0{l}^4}{3}$
3. $\frac{2{\lambda }_0{l}^3}{3}$
4. $\frac{{\lambda }_{0}l}{2}$

Q. Explain ± ne where n is an integer and e =1.6×10^-19C and what is C

Q. A positively charged rod is brought near an uncharged conductor. If the rod is suddenly withdrawn, the charge left on the conductor will be :

1. positive
2. negative
3. zero
4. cannot say