Answer:
1600 years half life
3200/1600 is 2 half lifes
first half life takes the sample to 1/2 it's original amount and the second takes it to 1/4 of it's original amount
so 1/4*7gm is 1.75gm
Explanation:
Answer:
Magnetic field at point having a distance of 2 cm from wire is 6.99 x 10⁻⁶ T
Explanation:
Magnetic field due to finite straight wire at a point perpendicular to the wire is given by the relation :
......(1)
Here I is current in the wire, L is the length of the wire, R is the distance of the point from the wire and μ₀ is vacuum permeability constant.
In this problem,
Current, I = 0.7 A
Length of wire, L = 0.62 m
Distance of point from wire, R = 2 cm = 2 x 10⁻² m = 0.02 m
Vacuum permeability, μ₀ = 4π x 10⁻⁷ H/m
Substitute these values in equation (1).

B = 6.99 x 10⁻⁶ T
Resistance = (voltage) / (current)
= 24 ohms.