Home / JEE / Physics / Magnetic Effects of Current and Magnetism
Magnetic Effects of Current and Magnetism
JEE Physics · 160 questions. Try each one, then check the answer and solution.
Log in to bookmark questions and track your accuracy chapter by chapter.
Q61.AI-generated practiceSingle-correct MCQEasy
Two long parallel wires 1 m apart in vacuum each carry a current of 1 A. The force per metre length between them is:
Q62.AI-generated practiceSingle-correct MCQEasy
Two long parallel wires carry currents in the same direction. The wires:
Q63.AI-generated practiceSingle-correct MCQMedium
Two long parallel wires 5 cm apart carry currents of 10 A and 20 A. The magnitude of the force per metre on each wire is (μ0 = 4π × 10-7 T m/A):
Q64.AI-generated practiceSingle-correct MCQMedium
A straight wire 50 cm long carries a current of 4 A in a uniform magnetic field of 0.3 T, at an angle of 30° to the field. The force on the wire is:
Q65.AI-generated practiceSingle-correct MCQMedium
A closed current-carrying loop of any shape is placed in a uniform magnetic field. The net magnetic force on the loop is:
Q66.AI-generated practiceSingle-correct MCQHard
A wire bent into a semicircle of radius R carries a current I. It lies in a plane perpendicular to a uniform magnetic field B. The net magnetic force on it is:
Q67.AI-generated practiceSingle-correct MCQMedium
A horizontal metal rod of mass 0.2 kg and length 1 m is placed in a uniform horizontal magnetic field of 0.5 T perpendicular to the rod. The current needed for the magnetic force to support the rod's weight is (g = 10 m/s2):
Q68.AI-generated practiceSingle-correct MCQHard
Three long parallel wires lie in a plane with equal separations d and carry equal currents I in the same direction. The force per unit length on one of the outer wires is:
Q69.AI-generated practiceSingle-correct MCQEasy
A straight wire along the +x axis carries a current in the +x direction in a uniform magnetic field along +y. The force on the wire is along:
Q70.AI-generated practiceSingle-correct MCQMedium
Two long parallel wires carry currents in opposite directions. The force between them is:
Q71.AI-generated practiceSingle-correct MCQMedium
The currents in two long parallel wires are both doubled, keeping the separation the same. The force between them becomes:
Q72.AI-generated practiceSingle-correct MCQHard
A square loop of side 10 cm carrying 2 A lies in the same plane as a long straight wire carrying 5 A. The side of the loop nearest the wire is parallel to it at 5 cm and carries current in the same direction as the wire. The net force on the loop is about (μ0 = 4π × 10-7 T m/A):
Q73.AI-generated practiceSingle-correct MCQMedium
A straight wire 0.2 m long carrying a current of 3 A lies along the direction of a uniform magnetic field of 0.5 T. The force on the wire is:
Q74.AI-generated practiceSingle-correct MCQMedium
Two long parallel wires 10 cm apart carry equal currents and attract each other with a force of 8 × 10-5 N per metre. The current in each wire is about (μ0 = 4π × 10-7 T m/A):
Q75.AI-generated practiceNumerical valueEasy
A straight wire 2 m long carries a current of 3 A perpendicular to a uniform magnetic field of 0.5 T. Find the force on it in newton.
Q76.AI-generated practiceNumerical valueMedium
Two long parallel wires 4 cm apart carry currents of 2 A and 5 A. Take μ0 = 4π × 10-7 T m/A. If the force on a 1 m length of either wire is x × 10-5 N, find x.
Q77.AI-generated practiceNumerical valueMedium
A metal rod 0.5 m long with mass 50 g hangs horizontally from two light flexible wires in a uniform horizontal magnetic field of 0.25 T perpendicular to the rod. Find the current (in ampere) in the rod for which the tension in the wires becomes zero. (g = 10 m/s2)
Q78.AI-generated practiceNumerical valueHard
Three long parallel wires A, B and C lie in one plane with B in the middle, 2 cm from each of the others. They carry currents of 10 A, 20 A and 10 A respectively, all in the same direction. Take μ0 = 4π × 10-7 T m/A. If the force per metre on wire C is x × 10-4 N/m, find x.
Q79.AI-generated practiceAssertion–ReasonMedium
Assertion (A): Two long parallel wires carrying currents in the same direction attract each other. Reason (R): Each wire lies in the magnetic field of the other, and the force IL × B on it points towards the other wire.
Q80.AI-generated practiceAssertion–ReasonHard
Assertion (A): A current-carrying closed loop of any shape placed in a uniform magnetic field experiences no net force. Reason (R): A current-carrying loop placed in a uniform magnetic field experiences no torque.