A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :
A full wave rectifier circuit with diodes (\(D_1\)) and (\(D_2\)) is shown in the figure. If input supply voltage \(V_{in} = 220 \sin(100 \pi t)\) volt, then at \(t = 15\) msec:
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
Stress and Strain are the terms in physics, which are used to explain deformation of solids.
Force applied per unit area is known as stress.
As a result of stress, change of shape is observed in the body. The change or deformity consequential to the stress acting on the body is called strain. Strain can be defined as the amount or measure of deformity that takes place due to the force applied on the object.
Strain is denoted with (ε). It has no units.
Longitudinal Strain = Δ L/L
The English scientist Robert Hooke, while studying spring and elasticity, noticed that many materials displayed an identical property when the stress-strain relationship was studied. There exists a linear region where the force required to stretch the material was proportional to the extension of the material; this is called Hooke’s law. Mathematically, the law is presented as:
F = -k.x
Where, F = the force
x = the extension length
k = spring constant in N/m