Answer:
The correct answer is 4R1
Explanation:
According to the given scenario ,the radius of the tightest curve on the same road without skidding is as follows:
As we know that
Centeripetal Acceleration is
= v^2 ÷ r
In the case when velocity becomes 2 times so the r would be 4 times
So, the radius of the tightest curve on the same road without skidding is 4R1
Given
v = 343 m/s
ac = 5g
ac = 5*9.8 m/s^2
ac = 49 m/s^2
where,
v: velocity
ac = centripetal aceleration
Procedure
We call the acceleration of an object moving in uniform circular motion—resulting from a net external force—the centripetal acceleration ac; centripetal means “toward the center” or “center seeking”.
Formula

The minimum radius not to exceed the centripetal acceleration is 2401 m.
Answer:
B = 0.135T
Explanation:
To find the magnitude of the magnetic field you use the following formula, for the torque produced by a magnetic field B in a loop:
(1)
τ: torque = 1.51*10^-5 Nm
I: current = 2.47mA = 2.47*10^-3 A
B: magnitude of the magnetic field
A: area of the loop = 4.97cm^2 = 4.97(10^-2m)^2=4.97*10^-4m^2
N: turns = 181
θ: angle between B and the magnetic dipole (same as the direction of the normal to the plane)
You replace the values of the parameters in (1). Furthermore you do B the subject of the formula:

The answer is C hope this helps <span />