A uniform magnetic field B is in a cylindrical region (radius 10cm). A 80cm uniform wire with resistance 4.0 ohms is bent into a square frame and placed on one side along a diameter of the cylindrical region.

Assuming Magnetic field increases at a constant rate 0.010T/s, what is the current induced in the frame?

Centripetal force can be expressed as the net force that acts on an object in order to maintain its movement in a circular motion. As per Newton’s first law of motion, until and unless an external force is applied to an object, it is till then going to continue to move along a straight path. This is the case of centripetal force. Centripetal force can be defined as the force which maintains an object unchanged while it is travelling in a circular way, although it is not a basic force.

• Electromagnetic force (EMF) can be defined as the force that exists in the universe.
• The electromagnetic force (EMF) can be expressed as the physical interaction occuring when electrically charged particles contact with each other.
• Electromagnetic force (EMF) is usually a composite of every magnetic and electrical force acting between charged particles.
• The electromagnetic force can both attract and repel.

Thus, as per the question, the following can be deduced:

• r = 10cm
• R = 4Ω
• dB/ dt = 0.010T

Hence,

dϕ/dt = dB/ dt A

E = dϕ/dt = dB/dt A

= 0.01(πr²/2) = 0.01×3.15×0.01/2 = 1.57×10⁻⁴

Therefore, i = E/R = 1.57×10^-4/4 = 0.39×10⁻⁴ 

= 3.9×10⁻⁴A

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