Class 12 Physics Important Chapter 5 Magnetism and Matter

Class 12 Physics Important Chapter 5 Magnetism and Matter Solutions English Medium As Per The New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters ASSEB Class 12 Physics Additional Solutions in English and select need one. NCERT Class 12 Physics Additional Solutions Download PDF. HS 2nd Year Physics Important Solutions.

Class 12 Physics Important Chapter 5 Magnetism and Matter

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. CBSE Class 12 Physics Additional Question Answer are part of All Subject Solutions. Here we have given HS 2nd Physics Important Solutions English Medium for All Chapters, You can practice these here.

Magnetism and Matter

Chapter: 5

IMPORTANT QUESTION AND ANSWER

Answer The Following Questions:

1. What is Gauss’s law in magnetism?

Ans: It states that the net magnetic flux through any closed surface is zero:

2. At a place, the horizontal component of earth’s magnetic field is B and angle of dip is 60°. What is the value of horizontal component of the earth’s magnetic field at equator? 

Ans: Horizontal component = B 

Angle of dip = δ = 60° 

Horizontal component = B_net x cos δ 

=B_net cos 60° 

B = B_net x 1 /2

B_net = 2B 

At equator, δ = 0

Horizontal component = Bnet * cos δ 

= 2B x cos 0 = 2B

3. In what way is the behaviour of a diamagnetic material different from that of a paramagnetic, when kept in an external magnetic field?

Ans. A diamagnetic specimen would move towards the weaker region of the field while a paramagnetic specimen would move towards the stronger region.

4. Define the term ‘magnetic declination’ at a given point on earth.

Ans. The angle between the geographical meridian and the magnetic meridian at a place is called the magnetic declination at that place.

5. Why should the material used for making permanent magnets have high coercivity?

Ans. High coercivity ensures that the em magnetisation of the material is not easily destroyed by stray magnetic fields or temperature variations.

6. What did Meissner actually observe which is known as Meissner effect?

Ans: Meissner observed that superconductors, when cooled below a certain critical temperature, expel all magnetic field lines from their interior, showing perfect diamagnetism. This phenomenon is called the Meissner Effect.

7. A current is flowing through a solenoid having 1000 turns per metre. Calculate the magnetic intensity, H.

Ans: The magnetic intensity is given by:

H = nI

Where,

n = 1000 turns/m

Without the value of current (I), H cannot be numerically calculated.

However, if I = 1 A (assumed), then.

H = 1000 × 1 = 1000 A/m. 

8. Obtain an expression for torque acting on a rectangular coil carrying current placed in a uniform magnetic field.

Ans: For a coil of N turns, area A, and current I, placed in a uniform magnetic field B, the torque is:

Where,

τ = NIABsinθ

Where θ is the angle between the magnetic moment and the magnetic field.

9. Find the expression for mutual inductance between a pair of co-axial coils.

Ans: (Not directly from this chapter but from Electromagnetic Induction)

If coil 1 carries current I, and flux linked with coil 2 is Φ₂₁

then mutual inductance M is defined as:

It depends on the geometry and relative orientation of the coils.

10. Define the elements of the earth’s magnetic field.

Ans: The three elements of Earth’s magnetic field are:

(i) Magnetic Declination (D): The angle between true geographic north and magnetic north.

(ii) Magnetic Inclination (Dip) (I): The angle made by Earth’s magnetic field with the horizontal.

(iii) Horizontal Component (H): The component of Earth’s magnetic field in the horizontal direction.

11. Of two metals A and B it is found that X_A >>1 and-1≤ X_B <O. Name the types of materials to which the metals A and B do belong. Give one example of each. 

Ans: If χ < 0 → Diamagnetic material (e.g., Bismuth, Copper)
If χ ≈ –1 → Perfect diamagnet (Superconductor).

12. Define magnetic declination. How does it depend on latitudes?

Ans: Magnetic declination is the angle between the geographic meridian and the magnetic meridian.

It varies with location (latitude and longitude) on Earth due to the irregular shape of Earth’s magnetic field.

13. Show that the emf induced in a conductor of length l and moving a distance x with velocity v perpendicular to magnetic field B is ε = Blv.

Ans: From Faraday’s law of electromagnetic induction:

14. In the above question if v=rqB/m. find its angular frequency (ω) and time period (T).

Ans: When a charged particle moves in a magnetic field:

Angular frequency (ω):

ω = qB/m 

Time period (T):