Answer:
C. An external downward field is created or an external downward field is removed
Explanation:
As we can see that from the attached figure that the induced current would be counter clockwise. So the field occur because of induced current i.e. out of page. This represent that the current is induced in order to rise the flux out of the direction of the page
Therefore because of the external field, the field out of page & flux would be reducing or the external upward field is eliminated
So option C is correct
Answer:
Time taken = 10400 s
Explanation:
Given:
Initial speed of the train, 
Final speed of the train, 
Displacement of the train, 
Using Newton's equation of motion,
Now, using Newton's equation of motion for displacement,
Now, plug in the value of 
in the above equation. This gives,
Now, plug in 234000 m for 
, 25 m/s for 
and 20 m/s for 
. Solve for 
.
Therefore, the time taken by the train is 10400 s.
C. electrical energy is transformed into light and heat energy
The question is incomplete. I can help you by adding the information missing. They want you to calculate a) the radius of the cyclotron orbit for an electron with speed 1.0 * 10^6 m/s^2 and b) the radius of a cyclotron orbit for a proton with speed 5.0 * 10^4 m/s.
The two tasks involve combining the equations of the magnectic force and the centripetal force in a circular motion.
When you do that, you will obtain an expression to find the radius of the circular motion, which is the radius of the cyclotron that impulses the particles.
a)
Magentic force, F = q*v*B
q is the charge of the electron = 1.6 * 10^ -19 C
v is the speed = 1.0 * 10 ^ 6 m/s
B is the magentic field = 5.0 * 10 ^-5 T
Centripetal force, F = m*Ac = m * v^2 / R
where,
Ac = centripetal acceleration
m = mass of the electron = 9.11 * 10 ^-31 kg
R = the radius of the orbit
Now equal the two forces: q*v*B = m * v^2 / R => R = m*v / (q*B)
=> R = (9.11 * 10^31 kg) (1.0*10^6m/s) / [ (1.6 * 10^-19C)* (5.0 * 10^-5T) ]
=> R = 0.114 m
b) The equations are the same, just now use the speed, charge and mass of the proton instead of those of the electron.
R = m*v / (qB) = (1.66*10^-27 kg)(5.0*10^4 m/s) / [(1.6*10^-19C)(5*10^-5T)]
=> R = 10.4 m
Acute health effects such as skin burns or acute radiation syndrome can occur when doses of radiation exceed certain levels.
