Question

Проводник массой 50 г и длиной 20см , подвешенный на двух нитях , находится в равновесии в магнитном поле индукцией 0.5 Тл.После того как по нему пустили ток,сила натяжения нити увеличилась в 2 разв. Чему равна сил тока ?

Answer 1

Calculation of Current

To calculate the current flowing through the conductor, we can use the relationship between the force of tension in the strings and the magnetic field.

Let's denote the force of tension in the strings before the current is passed through the conductor as T and the force of tension in the strings after the current is passed through the conductor as 2T.

According to the principle of equilibrium, the sum of the forces acting on the conductor in the vertical direction must be zero. This means that the weight of the conductor is balanced by the forces of tension in the strings.

Before the current is passed through the conductor, the weight of the conductor is balanced by the force of tension in the strings, so we have:

T = mg (Equation 1)

where m is the mass of the conductor and g is the acceleration due to gravity.

After the current is passed through the conductor, the force of tension in the strings becomes 2T. This increased force of tension is due to the interaction between the magnetic field and the current flowing through the conductor.

Using the equation for the force experienced by a current-carrying conductor in a magnetic field:

F = BIL (Equation 2)

where F is the force experienced by the conductor, B is the magnetic field induction, I is the current flowing through the conductor, and L is the length of the conductor.

Since the conductor is in equilibrium, the force of tension in the strings after the current is passed through the conductor is equal to the force experienced by the conductor:

2T = BIL (Equation 3)

Substituting Equation 1 into Equation 3, we get:

2mg = BIL (Equation 4)

Simplifying Equation 4, we can solve for the current I:

I = (2mg)/(BL) (Equation 5)

Now we can substitute the given values into Equation 5 to find the current.

Given: - Mass of the conductor (m) = 50 g = 0.05 kg - Length of the conductor (L) = 20 cm = 0.2 m - Magnetic field induction (B) = 0.5 T

Substituting these values into Equation 5, we get:

I = (2 * 0.05 * 9.8)/(0.5 * 0.2) = 0.98 A

Therefore, the current flowing through the conductor is approximately 0.98 A.