A wire is stretched to double its length .what happened to its resistance and resistivity?
1 answer:
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Answer:
The energy stored in the solenoid is 7.078 x 10⁻⁵ J
Explanation:
Given;
diameter of the solenoid, d = 2.80 cm
radius of the solenoid, r = d/2 = 1.4 cm
length of the solenoid, L = 14 cm = 0.14 m
number of turns, N = 200 turns
current in the solenoid, I = 0.8 A
The cross sectional area of the solenoid is given as;
The inductance of the solenoid is given by;
The energy stored in the solenoid is given by;
E = ¹/₂LI²
E = ¹/₂(2.212 x 10⁻⁴)(0.8)²
E = 7.078 x 10⁻⁵ J
Therefore, the energy stored in the solenoid is 7.078 x 10⁻⁵ J
Answer:
D)Not enough information
Explanation:
According to Pascal's principle, the pressure exerted on the two pistons is equal:
Pressure is given by the ratio between force F and area A, so we can write
The force exerted on each piston is just equal to the weight of the corresponding mass: , where m is the mass and g is the gravitational acceleration. So the equation becomes
Now we can rewrite the mass as the product of volume, V, times density, d:
We also know that
So we can further re-arrange the equation (and simplify g as well):
We are also told that block B has bigger volume than block A: . However, this information is not enough to allow us to say if the fraction on the right is greater than 1 or smaller than 1: therefore, we cannot conclude anything about the densities of the two objects.