Physics
AP EAMCET Physics carries 40 questions and samples mechanics, properties of matter, thermodynamics, oscillations and waves, optics, electricity and magnetism, electromagnetic induction, alternating current, dual nature, atoms/nuclei and semiconductor devices. Numerical items often join two ideas, so formula recall alone is not enough.
Core rules
- Projectile: T = 2u sinθ/g, H = u² sin²θ/(2g), R = u² sin2θ/g; maximum range occurs at 45°.
- Work–energy: W_net = ΔK; for a conservative force F = −dU/dx.
- Rotation: τ = Iα and L = Iω; rolling without slipping means v = ωR.
- SHM: spring T = 2π√(m/k); simple pendulum T = 2π√(l/g).
- Thin lens: 1/f = 1/v − 1/u with Cartesian sign convention; mirror: 1/f = 1/v + 1/u.
- AC: average power P_avg = V_rms I_rms cos φ.
Worked example
An object is 30 cm from a convex lens of focal length 20 cm. Find the image distance and magnification. Take light left to right; the object is on the left, so u = −30 cm and f = +20 cm. From 1/f = 1/v − 1/u, 1/v = 1/f + 1/u = 1/20 − 1/30 = 1/60, so v = +60 cm. The image is real and 60 cm on the opposite side. Magnification m = v/u = 60/(−30) = −2: inverted and twice the object size.
Traps
- Using sinθ instead of sin²θ in the maximum-height formula.
- Mixing lens and mirror sign conventions.
- Treating rms and peak values as interchangeable in AC power.
- Reversing series/parallel rules for resistance versus capacitance.