Earths Magnetism BH BV Declination Dip - UNSOLVED PRACTICE SET
Chapter: Magnetism and Matter | Topic: Earths Magnetism BH BV Declination Dip
EARTHS MAGNETISM BH BV DECLINATION DIP - UNSOLVED PRACTICE SET
Topic: Earths Magnetism BH BV Declination Dip
Multiple Choice Questions
Q1. The angle between the geographic meridian and the magnetic meridian at a place is called:
- Angle of dip
- Magnetic declination
- Horizontal component
- Magnetic inclination
Q2. At the magnetic equator, the angle of dip is:
- 0°
- 45°
- 90°
- 180°
Q3. At the magnetic poles of the Earth:
- B_H is maximum and B_V is zero
- B_H is zero and B_V is maximum
- Both B_H and B_V are equal
- Both B_H and B_V are zero
Q4. The horizontal component of Earth's magnetic field (B_H) is related to the total field (B) and angle of dip (δ) by:
- B_H = B × sin δ
- B_H = B × cos δ
- B_H = B / tan δ
- B_H = B × tan δ
Q5. If the angle of dip at a place is 60°, the ratio of horizontal to vertical component of Earth's magnetic field is:
- √3 : 1
- 1 : √3
- 1 : 2
- 2 : 1
Q6. Magnetic declination at a place depends on:
- Only latitude
- Only longitude
- Both latitude and longitude
- Neither latitude nor longitude
Short Answer Questions
Q7. Define magnetic declination. Why does it vary from place to place on Earth?
Q8. What is angle of dip (or magnetic inclination)? At which places on Earth is it 0° and 90°?
Q9. Write the relationship between the total Earth's magnetic field (B), horizontal component (B_H), vertical component (B_V), and angle of dip (δ).
Q10. A compass needle points slightly east of geographic north at a certain location. What does this indicate about the magnetic declination at that place?
Q11. Why is the horizontal component of Earth's magnetic field maximum at the equator and zero at the poles?
Q12. What would happen to a freely suspended magnetic needle if it were taken to the geographic north pole of the Earth?
Long Answer Questions
Q13. Explain the three elements of Earth's magnetism with the help of a neat diagram. Show how they are related to each other mathematically.
Q14. A magnetic needle free to rotate in a vertical plane at a certain place shows different behaviour at different latitudes. Explain why the angle of dip varies from 0° at the magnetic equator to 90° at the magnetic poles.
Q15. Explain with a diagram how you would determine the angle of dip at a given place using a dip circle. What precautions would you take during the experiment?
Numerical & Application-Based Problems
Q16. At a certain place, the horizontal component of Earth's magnetic field is 0.3 G and the angle of dip is 60°.
(a) Calculate the total intensity of Earth's magnetic field at that place.
(b) Find the vertical component of Earth's magnetic field.
(c) If a magnetic needle is placed at this location, at what angle to the horizontal will it come to rest?
Q17. The total Earth's magnetic field at a place is 0.5 G. The angle of dip at this place is 30°.
(a) Calculate the horizontal and vertical components of Earth's magnetic field.
(b) At another place, the horizontal component is found to be 0.2 G and the vertical component is 0.4 G. Calculate the angle of dip at this second place.
(c) Compare the magnetic behaviour of a compass needle at both places.
Q18. In a school geography project, students are studying Earth's magnetism across India. At Chennai (near the magnetic equator), the angle of dip is approximately 15° and the horizontal component of Earth's field is 0.37 G. At Delhi (farther north), the angle of dip is approximately 42°.
(a) Calculate the total Earth's magnetic field at Chennai.
(b) Calculate the total Earth's magnetic field at Delhi, assuming the horizontal component there is 0.30 G.
(c) A student argues that since the horizontal component is larger at Chennai, a compass needle would work 'better' there than in Delhi. Discuss whether you agree with this statement, giving reasons.