A rectangular coil is placed in a uniform magnetic field. If the direction of the current is reversed, what is the effect on the force acting on each segment of the coil?
The direction of the force on each segment reverses
The force on a straight current-carrying segment placed in a magnetic field is given by F = IL × B. Its direction is fixed by the direction of the current I and of the field B. When the current is reversed while B stays the same, the vector IL flips, and so does the cross product IL × B. The magnitude |F| = BIL sin θ depends only on the sizes of I, L, B and the angle, none of which change, so the size of the force is unchanged.
So the force on each side of the coil reverses in direction but keeps the same magnitude. It does not double, does not become zero, and it already acts in the plane perpendicular to both the current and the field, not perpendicular to the plane of the coil.
Hence, the answer is The direction of the force on each segment reverses.
Similar Questions
The direction of the magnetic field at the centre of a current-carrying circular loop is determined by which of the following?
A single-turn coil of radius R produces a magnetic field B at its centre. If the same wire is wound into a coil of n turns (each of radius R/n) carrying the same current I, what will be the value of the new field at the centre?
An electron enters a uniform magnetic field at right angles to it. If the magnetic field is directed into the page and the electron enters toward the right, what is the direction of the force acting on the electron?
A student wants to design a device where the magnetic field due to a straight conductor is maximized at a certain point. Which modification will be most effective in increasing the field strength at that point?
Why does one end of a solenoid behave as a north pole and the other as a south pole?
A student observes that the compass needle deflection decreases as it moves farther from a current-carrying straight conductor. What is the most likely reason for this observation?
A technician wants to decrease the magnetic effect around a current-carrying wire without changing the wire's material or environment. Which method should be used?
Which rule is used to determine the direction of the magnetic field at the centre of a circular current-carrying loop?
A student uses Fleming's Left Hand Rule to determine the direction of force on a conductor. If the forefinger points north, and the middle finger points east, in which direction will the force act?
If the direction of the magnetic field is north to south and the conductor moves upward, using Fleming's Right Hand Rule, what is the direction of the induced current?
Important Questions from Magnetism
What is the direction of magnetic field lines outside a magnet?
Which of the following statement is correct?
।. Magnetic field has both magnitude and direction.
II. The magnetic field inside a current-carrying straight long solenoid is the same at all points.
The magnetic effect of electric current was discovered by _____.
The important property of magnet which was exploited by navigators and travelers from the ancient times is:
The magnet used to lift and transport heavy loads like big metals, steel girders and scrap iron objects for loading and unloading purposes is known as____.
