Oersted's Experiment - UNSOLVED PRACTICE SET

Q7. Describe Oersted's experiment briefly. What was the key observation that Oersted made?

Q8. What conclusion did Oersted draw from his experiment? Why was this discovery considered revolutionary at the time?

Q9. In Oersted's setup, a compass is placed below a wire connected to a battery and switch. Describe what happens to the compass needle when:
(a) the switch is open,
(b) the switch is closed.

Q10. Why does reversing the direction of current in the wire reverse the direction of deflection of the compass needle in Oersted's experiment?

Q11. What happens to the deflection of the compass needle if the current in Oersted's experiment is increased? What does this tell us about the relationship between current and magnetic field strength?

Q12. Before Oersted's experiment, electricity and magnetism were thought to be completely separate phenomena. How did this single experiment change scientific understanding?

Q13. Describe Oersted's experiment in detail, including the setup, observations, and conclusions. Your answer must cover:
(a) the apparatus used (battery, wire, switch, compass),
(b) the arrangement — wire placed parallel to and above/below the compass needle,
(c) the observation when current flows in one direction,
(d) the observation when current direction is reversed,
(e) the observation when current is switched off, and
(f) the overall conclusion about the relationship between electric current and magnetism.

Q14. Design and describe a classroom version of Oersted's experiment that a Class 10 student in India could perform safely.
(a) List the materials needed (use safe, low-voltage components).
(b) Describe the step-by-step procedure.
(c) What precautions should be taken (e.g., regarding current magnitude and circuit duration)?
(d) Predict and explain what would happen if a stronger battery were used.
(e) How would the experiment demonstrate that the effect is due to the current and not due to the wire's material or heat?

Q15. Explain the historical and scientific significance of Oersted's discovery. Your answer must cover:
(a) the state of scientific understanding before 1820 regarding electricity and magnetism,
(b) what Oersted's experiment proved,
(c) how this discovery led to the development of electromagnets, electric motors, and generators,
(d) the broader field of 'electromagnetism' that emerged as a result, and
(e) name and briefly describe one device used in daily Indian life that exists because of this discovery.

Q16. A straight current-carrying wire runs from East to West, and a compass is placed directly below it, initially pointing North.
(a) When current flows from East to West, the compass needle deflects toward the North-West. Using this information and the right-hand thumb rule (which you will study in detail in the next topic), what is the direction of current flow?
(b) If the current is now reversed (West to East), predict the new direction of deflection.
(c) If the compass is moved to a position directly ABOVE the wire (instead of below), how would the deflection direction change for the same current direction?

Q17. In an Oersted-type setup, a student records the deflection angle of the compass for different currents:  Current (A): 0.5  1.0  1.5  2.0
Deflection (°): 10   20   28   35
(a) Plot (or describe) the graph of deflection angle vs current.
(b) Is the relationship perfectly linear?
(c) Why might the deflection not increase exactly proportionally at higher currents (consider that compass deflection follows tan θ ∝ B ∝ I, not θ ∝ I directly)?
(d) Estimate the deflection for a current of 2.5 A based on the trend.

Q18. A teacher demonstrates Oersted's experiment to a class using a wire connected to a 6 V battery through a rheostat (variable resistance) and a switch.
(a) Explain the purpose of the rheostat in this circuit.
(b) If the compass shows no deflection at all when the switch is closed, list three possible faults in the circuit that could explain this.
(c) The teacher then places a second compass on the other side of the wire (wire between the two compasses). Predict and explain what each compass would show.