Cathode ray tubes in old television sets worked by accelerating electrons and then deflecting them with magnetic fields onto a p
hosphor screen. The magnetic fields were created by coils of wire on either side of the tube carrying large currents. In one such TV set, the phosphor screen is 51.2 cm wide, and is 11.1 cm away from the center of the magnetic deflection coils (that is, the center of the region of magnetic field). The electron beam is first accelerated through a 22,000 V potential difference before it enters the magnetic field region, which is 1.00 cm wide. The field is approximately uniform and perpendicular to the velocity of the electrons. If the field were turned off, the electrons would hit the center of the screen. What magnitude of magnetic field (in mT) is needed to deflect the electrons so that they hit the far edge of the screen
1 answer:
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The mass of the ion is 5.96 X 10⁻²⁵ kg
<u>Explanation:</u>
The electrical energy given to the ion Vq will be changed into kinetic energy
As the ion moves with velocity v in a magnetic field B then the magnetic Lorentz force Bqv will be balanced by centrifugal force .
So,
and
Right from these eliminating v, we can derive
On substituting the value, we get:
m = 5.96 X 10⁻²⁵ kg.
Answer:
The correct option is;
Man doing most work
Box gaining the most energy
D Y Q
Explanation:
The given parameters of the question are;
The distance the box P is pushed by the Man X = 0
The force the Man X applies to the box P = x N
The distance the box Q is lifted by the Man Y = h > 0 meters
The minimum force the Man Y applies to the box Q = W, the weight of the box
Work done = Force × Distance
Energy gained = Potential energy + Kinetic Energy = (Mass × Gravity × Height = Weight × Height = W × h) + 1/2 × Mass × Velocity²
The final velocity of either box = 0 m/s (The boxes are at rest on the ground or the shelf)
Therefore, Kinetic energy = 0 J
The work done by Man X = 0 × x = 0 J
The energy gained by the box P = W × 0 = 0 J
The work done by Man Y = W × h = W·h J
The energy gained by the box P = W × h = W·h J
We have, the work done by the man Y = W·h J is more than the work done by the man X = 0 J
The energy gained by the box P = W·h J is more than the energy gained by the box Q = 0 J
Therefore, the correct option is D, Man doing the most work is Y, box gaining the most energy is Q.