Physics
The speed of rotation of coil can be increased by :
- decreasing the strength of the magnetic field
- decreasing the area of the coil
- increasing the area of the coil
- decreasing the number of turns in the coil
Answer
increasing the area of the coil
Reason — One way to increase the speed of rotation of coil, is by increasing the area of the coil. When the area of the coil is increased, more magnetic field lines are intersected as the coil rotates, leading to a greater change in magnetic flux and hence a higher induced EMF and higher speed of rotation.
Related Questions
A charge moving in a magnetic field in a direction other than the direction of the magnetic field experiences a force called :
- Lorentz force
- Nuclear force
- Electric force
- Gravitational force
The magnitude of force acting on a current carrying wire placed in a magnetic field in a direction perpendicular to its length depends on :
- The current flowing in the wire
- The strength of the magnetic field
- The length of the wire
- all of the above
The function of a split ring commutator is to :
- increase the magnetic field
- increase the current
- reverse the direction of the current
- none of the above
Four wires each of length 2 m are bent in the form of four loops P, Q, R and S as shown below. They are suspended in a uniform magnetic field. Each loop carries the same current. Identify the correct statement.
- torque on loop P is maximum.
- torque on loop Q is maximum.
- torque on loop R is maximum.
- torque on loop S is maximum.