# Chapter-1 Electric Charges and Fields (Sample Test-1)

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Chapter-1 Electric Charges and Fields (Sample Test-1)

1.
Plastic rod rubbed with fur and glass rod rubbed with silk

(A) repel each other
(B) mix up with each other
(C) attract each other
(D) None of the aboveDeselect Answer

2.
Electric charge between two bodies can be produced by

A) sticking
(B) rubbing
(C) oiling

3.
Electric charges under action of electric forces is called

(A) electrostatic
(B) electric flux
C) electric field

4.
Law stating that “force is directly proportional to product of charges and inversely proportional to square of separation between them” is called

(A) Newton’s law
(B) Coulomb’s law
(C) Gauss’s law

5.
In given figure, two positive charges q2 and q3 fixed along the y axis, exert a net electric force in the + x direction on a charge q1 fixed along the x axis. If a positive charge Q is added at (x, 0), the force on q1

(A) shall increase along the positive x-axis.
(B) shall decrease along the positive x-axis.
(C) shall point along the negative x-axis.
(D) shall increase but the direction changes because of the intersection of Q with q2 and q3Deselect Answer

6.
The magnitude of electric force, F is

(A) directly proportional to the multiplication of both charges.
(B) directly proportional to the distance between both charges.
(C) directly proportional to the square of the distance between both charges.

7.
A body is negatively charged means

(A) It has only negative charges.
(B) Positive charges have been neutralized by negative charges.
(C) The quantity of negative charge present is more than the quantity positive charge present.
(D) The positive are displaced from their original positionsDeselect Answer

8.
When a body is charged by conduction, its mass

(A) remains same
(B) increases
(C) decreases

9.
A point positive charge is brought near an isolated conducting sphere in Figure. The electric field is best given by :

(A) Fig (i)
(B) Fig (iii)
(C) Fig (ii)

10.
A point charge +q, is placed at a distance d from an isolated conducting plane. The field at a point P on the other side of the plane is

(A) directed perpendicular to the plane and away from the plane.
(B) directed perpendicular to the plane but towards the plane.
(C) directed radially away from the point charge.

11.
A hemisphere is uniformly charged positively. The electric field at a point on a diameter away from the centre is directed

(A) perpendicular to the diameter.
(B) parallel to the diameter.
(C) at an angle tilted towards the diameter.
(D) at an angle tilted away from the diameter.Deselect Answer

12.
The electric flux through the surface :

(A) in Figure (iv) is the largest.
(B) in Figure (iii) is the least.
(C) in Figure (ii) is same as Figure (iii) but is smaller than Figure (iv).
(D) is the same for all the figuresDeselect Answer

13.
Figure shows electric field lines in which an electric dipole p is placed as shown. Which of the following statements is correct?

(A) The dipole will not experience any force.
(B) The dipole will experience a force towards right.
(C) The dipole will experience a force towards left.
(D) The dipole will experience a force upwards.Deselect Answer

14.
Five charges q1, q2, q3, q4, and q5 are fixed at their positions as shown in Figure. S is a Gaussian surface. The Gauss’s law is given by:

Which of the following statements is correct?
(A) E on the LHS of the above equation will have a contribution from q1, q5 and q3, while q on the RHS will have a contribution from q2 and q4 only.
(B) E on the LHS of the above equation will have a contribution from all charges, while q on the RHS will have a contribution from q2 and q4 only.
(C) E on the LHS of the above equation will have a contribution from all charges, while q on the RHS will have a contribution from q1, q3 and q5 only.
(D) Both E on the LHS and q on the RHS will have contributions from q2 and q4 onlyDeselect Answer

15.
The Electric field at a point is

(A) always discontinuous.
(B) discontinuous if there is a positive charge at that point.
(C) discontinuous only if there is a negative charge at that point.
(D) discontinuous if there is a charge at that point.Deselect Answer

16.
If there is only one type of charge in the universe, the
17.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): In a non-uniform electric field, a dipole will have translatory as well as rotatory motion.
Reason (R): In a non-uniform electric field, a dipole experiences a force as well as torque.

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

18.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): The basic difference between magnetic lines of force and electric lines of force is electric lines of force are discontinuous and magnetic lines of force are continuous.
Reason (R): Magnetic lines of force exist in a magnet but no electric lines of force exists in a charged body

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

19.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Electric lines of force cross each other.
Reason (R): The resultant electric field at a point is the superimposition of the electric fields at that point.

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

20.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): When bodies are charged through friction, there is transfer of charge from one body to another. No charge is created or destroyed.
Reason (R): This is according to the law of conservation of electric charge

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

21.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): If two spherical conductors of different radii have the same surface charge densities, then their electric field intensities will be equal.
Reason (R): Surface charge density = Total charge / area

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

22.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): In a cavity in a conductor, the electric field is zero.
Reason (R): Charges in a conductor reside only at its surface

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

23.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Three point charges Q1, Q2 and Q3 are shown in the figure. The flux over the Gaussian surface depends on only one charge point.

Reason (R): Electric flux depends on the all charges nearby.

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

24.
Directions : In the following questions, A statement of Assertion (A) is followed by a statement of Reason (R). Mark the correct choice as.

Assertion (A): Using Gauss law, it is possible to find the electric field at any point.
Reason (R): Gauss law is applicable for any type of charge distribution.

(A) Both A and R are true and R is the correct explanation of A
(B) Both A and R are true but R is NOT the correct explanation of A
(C) A is true but R is false
(D) A is false and R is trueDeselect Answer

25.
Faraday Cage: A Faraday cage or Faraday shield is an enclosure made of conducting material. The fields within a conductor cancel out with any external fields, so the electric field within the encloser is zero. These Faraday cages act as big hollow conductors you can put things in to shield them from electrical fields. Any electrical shocks the cage receives, pass harmlessly around the outside of the cage.

1. Which of the following material can be used to make a Faraday cage ?
(A) Plastic (B) Glass (C) Copper (D) Wood

2. Example of a real-world Faraday cage is :
(A) car (B) plastic box (C) lighting rod (D) metal rod

3. What is the electrical force inside a Faraday cage when it is struck by lightning ?
(A) The same as the lightning
(B) Half that of the lightning
(C) Zero
(D) A quarter of the lightning

4. If isolated point charge +q is placed inside the Faraday cage. Its surface must have charge equal to :
(A) Zero (B) +q (C) –q (D) +2q

5. A point charge of 2 C is placed at centre of Faraday cage in the shape of cube with surface of 9 cm edge. The number of electric field lines passing through the cube normally will be :
(A) 1.9 × 10^5 Nm²/C entering the surface.
(B) 1.9 × 10^5 Nm²/C leaving the surface.
(C) 2.0 × 10^5 Nm² /C leaving the surface.
(D) 2.0 × 10^5 Nm²/C entering the surfaceDeselect Answer

26.
Tribo-electric series: The tribo-electric series is a list that ranks materials according to their tendency to gain or lose electrons. The process of electron transfer as a result of two objects coming into contact with one another and then separating is called tribo-electric charging. During such an interaction, one of the two objects will always gain electrons (becoming negatively charged) and the other object will lose electrons (becoming positively charged). The relative position of the two objects on the tribo-electric series will define which object gains electrons and which object loses electrons. In tribo-electric series, materials are ranked from high to low in terms of the tendency for the material to lose electron. If an object high up on this list (Glass, for example) is rubbed with an object low down on the list (Teflon, for example), the glass will lose electrons to the teflon. The glass will, in this case, become positively charged and the teflon will become negatively charged. Materials in the middle of the list (steel and wood, for example) are items those do not have a strong tendency to give up or accept electrons.

1. Materials in the upper position has _____ tendency to become positively charged.
(A) low (B) high (C) no (D) medium

2. Name two materials which do not have a strong tendency to give up or accept electrons.
(A) Ebonite, Nylon (B) Plastic wrap, Teflon (C) Nylon, cat fur (D) Steel, wood

3. If human hair is rubbed with amber, how those will be charged?
(A) Both negative
(B) Both positive
(C) Hair will be positively charged, Amber will be negatively charged.
(D) Hair will be negatively charged, Amber will be positively charged.

4. Tribo-electric charging is the process of electron transfer between two objects
(A) By contact
(B) Without contact
(C) By any one of the above
(D) By none of the above

5. The object which loses electron becomes _____charged and the object gains electron becomes______ charged.
(A) negatively, negatively
(B) positively, positively
(C) positively, negatively