Total resistance= 7.75+15.5+21.7=44.95
Current = 15V/44.95=0.334A
Answer: 0.04139m
Explanation:
First, we need to calculate the weight of the man which will be:
Weight = mass × acceleration due to gravity
Weight = mg
Weight = 92.5 × 9.8
Weight = 906.5N
Then, we calculate the force which will be:
F = kx
mg = kx
x = mg/k
x = 906.5/21900
x = 0.04139m.
The spring stretched for 0.04139m.
To protect a material from the influence of an external magnetic field, the material should be kept in soft iron ring.
So the correct answer is A.
Hope this helps,
Davinia.