A veritical brass rod of circular section is loaded by placing a 10 kg wt on top of it .if it's length is 1 m. it's radius of cross section 1cm find the energy stored in rod .Y=3.5 ×10^10 Nm2​

Energy stored in the rod, W = 4.55 × 10⁻⁴ J

Explanation:

From the question, the following values are given:

Mass of the brass rod, m = 10kg

Length of rod, l = 1 m

Radius of brass rod, r  =1 cm

Change in length of rod, e = ?

Energy stored, W = ?

Young's modulus of brass, Y = 3.5 × 10¹⁰ N/m²

Using the formula for energy stored in an elastic material;

W = 1/2 F × e

Force due to the load, F = mg =  10 × 10 = 100N

To determine the change in length, e, we use the formula for Young's modulus of elasticity;

Y = (F/A)/(e/l) = F × l / A × e  

e = (F × l) / (Y × A)

where A = πr²

e = 100 ×  1 / (3.5 × 10¹⁰ × π × (0.01)²

e = 9.09 × 10⁻⁶ m

Therefore, energy stored in the rod, W =  1/2 × 100 × 9.09 × 10⁻⁶

Energy stored in the rod, W = 4.55 × 10⁻⁴ J

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia