CBSE Class 10 Science 2022 · Paper 31/2/2 · Question 14
A student was asked to perform an experiment to study the force on a current carrying conductor in a magnetic field. He took a small aluminum rod AB, a strong horse shoe magnet, some connecting wires, a battery and a switch and connected them as shown. He observed that on passing current, the rod gets displaced. On reversing the direction of current, the direction of displacement also gets reversed. On the basis of your understanding of this phenomenon, answer the following questions :
- (a)Why does the rod get displaced on passing current through it ?
- (b)State the rule that determines the direction of the force on the conductor AB.
- (c)(i)(i) In the above experimented set up, when current is passed through the rod, it gets displaced towards the left. What will happen to the displacement if the polarity of the magnet and the direction of current both are reversed ? (ii) Name any two devices that use current carrying conductors and magnetic field.
- (c)(ii)OR : Draw the pattern of magnetic field lines produced around a current carrying straight conductor held vertically on a horizontal cardboard. Indicate the direction of the field lines as well as the direction of current flowing through the conductor.
Answer
(a) The rod carries a current and lies in the magnetic field of the horseshoe magnet. A current-carrying conductor placed in a magnetic field experiences a force (the field of the current interacts with the field of the magnet), and this force, acting at right angles to both the rod and the field, pushes the rod sideways.
(b) Fleming's left-hand rule: stretch the thumb, forefinger and middle finger of the left hand so that they are mutually perpendicular. If the forefinger points in the direction of the magnetic field and the middle finger in the direction of the current, the thumb points in the direction of the force, that is, of the motion of the conductor.
(c)(i) (i) The rod is still displaced towards the left. Reversing the polarity of the magnet alone would reverse the force, and reversing the current alone would reverse it too; reversing both reverses it twice, so its direction is unchanged (and, with the same current and magnet, so is its size). (ii) The electric motor and the loudspeaker (others: the electric generator, the microphone, and measuring instruments such as the galvanometer).
OR
(c)(ii) The field lines are concentric circles on the cardboard, centred on the conductor and spaced wider apart farther from it. With the current flowing upward through the conductor they run anticlockwise as seen from above (right-hand thumb rule); with a downward current they run clockwise.
🔒 Step-by-step solution
Sign up free to see every step of how it is worked out.
From the board paper
More questions from Magnetic Effects of Electric Current
Class 10 Science — every question with an expert-verified, step-by-step solution.
- Q1 Which of the following correctly describes the magnetic field nea…
- Q1 Why does a compass needle get deflected when brought near a ba…
- Q2 At the time of short circuit, the current in the circuit
- Q3 State whether the following statements are true or false. (a) The fie…
- Q4 List two methods of producing magnetic fields.
- Q5 When is the force experienced by a current–carrying conductor pl…
- Q6 Imagine that you are sitting in a chamber with your back to one wall…
- Q7 State the rule to determine the direction of a (i) magnetic field p…
- Q8 When does an electric short circuit occur?
- Q9 What is the function of an earth wire? Why is it necessary to e…
- Q1 Draw magnetic field lines around a bar magnet.
- Q2 List the properties of magnetic field lines.
All 279 questions on Magnetic Effects of Electric Current → Browse all Science chapters →