Two ends of a horizontal conducting rod of length l are joined to a vo...
Explanation:
When a conductor moves in a magnetic field, an induced emf is generated in the conductor. This phenomenon is known as electromagnetic induction. According to Faraday's law of electromagnetic induction, the induced emf is given by the equation:
E = -N(dΦ/dt)
Where E is the induced emf, N is the number of turns in the conductor (which is 1 in this case), and dΦ/dt is the rate of change of magnetic flux through the conductor.
In this scenario, the conducting rod is moving horizontally with a velocity v, perpendicular to the rod. The rod is also placed in a vertical component of the Earth's magnetic field B. Let's analyze the situation step by step.
Step 1: Determine the magnetic flux through the conductor
The magnetic flux through the conductor is given by the equation:
Φ = B*A*cosθ
Where B is the magnetic field, A is the area of the conductor, and θ is the angle between the magnetic field and the normal to the conductor. In this case, the angle is 90 degrees as the magnetic field is perpendicular to the rod.
Step 2: Calculate the rate of change of magnetic flux
Since the rod is moving horizontally, the area of the conductor exposed to the magnetic field is changing. The rate of change of magnetic flux is given by the equation:
(dΦ/dt) = -(dB/dt)*A*cosθ
Where dB/dt is the rate of change of the magnetic field. In this case, the magnetic field is constant, so dB/dt is zero.
Step 3: Calculate the induced emf
Substituting the values into the equation for induced emf, we get:
E = -N(dΦ/dt)
E = 0
Since the rate of change of magnetic flux is zero, the induced emf is zero.
Step 4: Interpret the voltmeter reading
The voltmeter measures the potential difference across the conducting rod. In this case, since the induced emf is zero, the voltmeter reading is zero.
Conclusion:
The correct answer is option B. The voltmeter reads zero because the induced emf is zero when the conducting rod moves horizontally in a magnetic field perpendicular to it.
Two ends of a horizontal conducting rod of length l are joined to a vo...
Since it is perpendicular so cos 90 = 0