Shortcut Methods
JEE (Advanced) Level:
1. Young’s Modulus (Y)
- Shortcut: Y = (UTS / Strain at Yield Point)
- Trick: Remember the approximate values for steel, aluminum, copper, and rubber.
2. Poisson’s Ratio (v)
- Shortcut: v = (Lateral Strain / Axial Strain)
- Trick: Poisson’s ratio is always positive and less than 0.5.
3. Bulk Modulus (K)
- Shortcut: K = (3 * Y * (1 - 2v)) / (1 + v)
- Trick: The bulk modulus of liquids and gases is very small compared to solids.
4. Shear Modulus (G)
- Shortcut: G = (UTS / (2 * Strain at Yield Point))
- Trick: Shear modulus represents the material’s resistance to deformation under shear forces.
5. Ultimate Tensile Strength (UTS)
- Shortcut: UTS = (Load at Failure / Original Cross-sectional Area)
- Trick: UTS is a key parameter in material selection for load-bearing applications.
6. Yield Strength (YS)
- Shortcut: YS = (Load at Yield Point / Original Cross-sectional Area)
- Trick: Yield strength is crucial in determining a material’s elastic limit.
7. Compressive Strength (CS)
- Shortcut: CS = (Load at Failure / Original Cross-sectional Area)
- Trick: Compressive strength is important for materials used in compression applications.
8. Brinell Hardness (HB)
- Shortcut: HB = (Load / Surface Area of Indentation)
- Trick: Brinell hardness is typically measured using a 10 mm diameter hardened steel ball.
9. Vickers Hardness (HV)
- Shortcut: HV = (Load / Surface Area of Indentation)
- Trick: Vickers hardness is measured using a diamond indenter with a square-based pyramid shape.
CBSE Board Level:
The shortcut methods and tricks for the CBSE board level are essentially the same as those mentioned for the JEE (Advanced) level. The key difference lies in the approximate values provided for the material properties.
Remember that these shortcuts and tricks should be used as supplementary aids to enhance problem-solving efficiency. A thorough understanding of the fundamental concepts and formulas is essential for mastering these numericals.