Case Study Questions Class 12 Physics Chapter 1 Electric Charges and Fields
CBSE Class 12 Case Study Questions Physics Electric Charges and Fields. Here we have arranged some Important Case Base Questions for students who are searching for Paragraph Based Questions Electric Charges and Fields.
At Case Study Questions there will given a Paragraph. In where some Important Questions will made on that respective Case Based Study. There will various types of marks will given 1 marks, 2 marks, 3 marks, 4 marks.
1.) Read the following paragraph and answer the following questions from 1.1 to 1.4 :
Charge is a property of matter that can be in two forms: positive charge and negative charge. If two objects which are having the same sign of charge repel to each other, and on the other hand objects which have opposite sign charges attract to each other. Electric field concept comes from
The concept of an electric field arises from the effect of a charge body in the space around the body. When a charged particle is placed in a space and it feels some electric force we can say there is an electric field.
Electric field is a vector quantity that means it has magnitude and direction both.
Electric field at any point can be defined as a force on a unit charge particle.
This unit charge is called a test charge, and the direction of the electric field is defined as a force direction on a positive test charge , and force on a charge particle in an electric field is given by F=qE.
1.1 Define electric field and how we can find direction of electric field ?
1.2 Choose the correct options from the following given below.
If two bodies have like charges and opposite charges how will they behave ?
A.) In both cases they will repel.
B.) In both cases they will attract.
C.) They will repel when both have the same charge and attract each other when both have opposite charges.
D.) They will attract when both have the same charge and repel each other when both have opposite charges.
1.3 If Force acting on a test charge of 5C , is 25 N along north direction then what will be electric field intensity at that point.
Answer 1.1
Electric field or electric field intensity at any point can be defined as a force on a unit charge particle. And we know that force on a charge particle is given by F=qE
From them we can wright E = F/q
And the direction of the electric field will be along the force on the positive charge particle or on the negative charge particle opposite to the force direction.
Answer 1.2
(C) They will repel when both have the same charge and attract each other when both have opposite charges.
When both bodies have the same charges they will repel each other and on the other hand they will attract each other when both bodies have different charges.
Answer 1.3
Given test charge value = 5C
And force on the test charge is 25N
We know that electric field intensity is defined as the force on per unit test charge.
So E = F/q = 25/5 = 5 N/C
And Direction of the electric field intensity is along the force direction that is along the north.
2.) Read the following paragraph and answer the following questions from 2.1 to 2.3
Electric field is a basic property of a charge particle. When a charge particle is placed in a space it will create an electric field around it in all possible directions and that will be inversely proportional to the square of the distance from the point charge.
As we know electric field is a vector quantity so due to more than one point charges electric field intensity can be calculated at any point as a vector sum of due to all point charges intensity and direction will be along the resultant vector direction.If at any point electric field is uniform can be drawn as a parallel line and if electric field is non- uniform it can be drawn non-parallel line but when then electric field line near to each other we can say there is a strong electric field compare to other point, where electric field line is little bit far away that means we can say electric field line density is directly proportional to electric field strength.And this electric field lines never intersect to each other. The electric field strength measure in V/m
2.1 How can electric field strength be measured ? And what is its SI unit ?
2.2 Why electric field lines never intersect with each other?
2.3 Let there be two point charges in space. Charge Q1= +3 μC is at coordinates (0, 0), and charge Q2 = -1 μC is at coordinates (6m, 0). Calculate the resultant electric field at a point P, which is at (3m, 0m), and also calculate force by this electric field on a +2 μC test charge which is placed at the same point P(3m,0).
Answer 2.1
Electric field can be measure by two ways:
1.) By placing a test charge on that point we can measure the electric field strength, first we calculate the force on test charge and we divide test charge value to force by this method we can calculate the electric field.
2.) Or if we know the field pattern we can say where the electric field is high in magnitude and where is low but by this method we can not determine magnitude of electric electric field strength.
And It’s SI unit is defined is a Volt/meter
Answer 2.2
Electric field lines never intersect with each other , because if electric field vector quantity means it has both magnitude and direction as well , if electric field lines intersect to each other we can be drawn to tangents on intersecting points which show its two directions at the same point which is impossible. Means electric field lines never intersect to each other.
3.) Read the following paragraph and answer the following questions from 3.1 to 3.3
When two charge or more charged particle placed at a distance then they will create a magnetic field due to this electric field they will exert an electric force on each other, this force can be calculated by Coulomb’s law, which states that force between two charge particles is directly proportional to magnitude of the charge particle and inversely proportional to square distance between them.Coulomb’s force between two charged particle depends on medium between them , when a medium of dielectric constant K is placed between two charged particle electric force decrease by K times
3.1 when two charges, q_1and q_2 are brought closer to each other without changing their magnitude, what will be the effect on electrostatic force between them?
A.) Decrease
B.) Increase
C.) Remain same
D.) Data is not sufficient
3.2 Two charge values of +2 μC and -4 μC are placed at 2m distance. Find the electrostatic force between these two charge particles?
3.3 Choose the correct statement from the given below.
Assertion(A): Electric force between two point charges depends upon the magnitudes of the two charges and also depends upon the distance between them.
Reason(R): Coulomb’s law defines the electrostatic force (F) is directly proportional to the product of magnitude of their charges and inversely proportional to the square of the distance (r) between two charges.
A. Both Assertion and Reason are true, and Reason is the correct explanation of reason.
B. Both Assertion and Reason are true, but Reason is NOT the correct explanation of Assertion.
C. Assertion is true, but Reason is false.
D. Assertion is false, but Reason is true
Answer 3.1
when two charges, and are brought closer to each other without changing their magnitude, electrostatic force between them will increase because force is inversely proportional to distance square.
Answer 3.2
By Coulomb’s law electrostatic force (F) between two point charges can be
Answer 3.3
A. Both Assertion and Reason are true, and Reason is the correct explanation of reason. By Coulomb’s law we can explain it.