Electronics & Circuits, Materials Science, and Mechanics Concepts

Flashcards covering fundamental concepts in Electronics and Circuits, Materials Science, and Mechanics.

Ohm’s Law

Relates voltage, current, and resistance in a circuit (V = IR).

Resistance of a Conductor

R = ρl/A, where R is resistance, ρ is resistivity, l is length, and A is the cross-sectional area.

Electrical Power

P = VI, P = I²R, P = V²/R, used to calculate energy dissipation in resistors.

Series Resistors

Total resistance RT = R1 + R2 + … when resistors are connected end-to-end.

Parallel Resistors

Total resistance 1/RT = 1/R1 + 1/R2 + … when resistors share the same voltage.

Voltage Divider

Equation Vx = VT * (Rx/RT) to obtain a fraction of the supply voltage.

Normal Stress

σ = F/A, measures force intensity within a material.

Normal Strain

ε = ΔL/L0, measures deformation relative to original size.

Young’s Modulus

E = σ/ε, indicates material stiffness.

Shear Stress

τ = F/A, force acting parallel to the surface.

Poisson’s Ratio

ν = - εlateral/εaxial, describes sideways contraction during stretching.

Newton’s Second Law

F = ma, defines the relationship between force, mass, and acceleration.

Force Components

Fx = Fcosθ, Fy = Fsinθ; used to resolve forces into perpendicular directions.

Resultant Force

FR = √(Fx² + Fy²), the vector sum of forces.

Moment (Torque)

M = Fd, measures the turning effect of a force.

Equilibrium Conditions

∑Fx = 0, ∑Fy = 0, ∑M = 0, required for static equilibrium.

Conductance

G = 1/R, the measure of how easily electric current flows through a conductor.

Shear Modulus

G = τ/γ, measures material's response to shear stress and strain.

Bulk Modulus

K = -ΔP/(ΔV/V), measures a material's resistance to uniform compression.

True Stress

σt = F/A_instant, stress calculated using instantaneous area.

True Strain

εt = ln(L/L0), a logarithmic measure of strain.

Moment from Components

M = (Fx⋅y) - (Fy⋅x), calculates moments using force components.

Moment of a Couple

M = Fz, the moment generated by two equal and opposite forces.

α (Direction of Resultant)

α = tan⁻¹(Fy/Fx), angle of the resultant force relative to the horizontal.

Internal Resistance

Vout = V * (RL/(RL + r)), calculates voltage across a load considering internal resistance.

Cross-Sectional Area

The area of the cut surface of a material through which force acts.

Resistivity

ρ, a material property that quantifies how strongly it resists electric current.

Current Divider (two resistors)

I1 = IT(R2/R1+R2) Used when resistors share the same voltage.

Shear strain

γ = Δx/h A measure of deformation representing the displacement between particles in a material, defined as the change in length (Δx) divided by the original height (h).