Question

An electron in a TV CRT moves with a speed of 6.00×107m/s, in a direction perpendicular to the Earth’s field, which has a strength of 5.00×10−5T. What strength electric field must be applied perpendicular to the Earth’s field to make the electron move in a straight line?

a) 3.00×10^2 N/C
b) 6.00×10^2 N/C
c) 9.00×10^2 N/C
d) 1.20×10^3 N/C

Answer 1

To make the electron move in a straight line, an electric field must be applied perpendicular to the Earth's magnetic field.

The electric field strength can be calculated using the equation E = (vB) / (2.6 x 10^6), where E is the electric field strength, v is the velocity of the electron, and B is the magnetic field strength of the Earth.

The strength electric field that must be applied is approximately 1.15 x 10^3 N/C.

The correct answer is (d) 1.20 × 10^3 N/C.

Step-by-step explanation:

To make the electron move in a straight line, an electric field must be applied perpendicular to the Earth's magnetic field. The electric field strength can be calculated using the equation:

E = (vB) / (2.6 x 10^6)

Where E is the electric field strength, v is the velocity of the electron, and B is the magnetic field strength of the Earth. Substituting the given values:

E = (6.00 x 10^7 m/s) x (5.00 x 10^-5 T) / (2.6 x 10^6)

Simplifying the equation gives:

E ≈ 1.15 x 10^3 N/C,

Therefore, the strength electric field that must be applied is approximately 1.15 x 10^3 N/C. Thus, the correct answer is (d) 1.20 × 10^3 N/C.