Science Group
Explore subjects and practice MCQs
7
Chapters
1,610
Total MCQs
Science Group
Answer: Energy stored in a capacitor = ½CV² = ½Q²/C = ½QV
Answer: A transformer works on the principle of mutual electromagnetic induction between primary and secondary coils.
Answer: A superconductor has exactly zero electrical resistance below its critical temperature.
Answer: Each part has resistance R/n. In parallel: 1/Req = n/(R/n) = n²/R → Req = R/n²
Answer: λ = h/mv, so the de Broglie wavelength is inversely proportional to the velocity (momentum) of the particle.
306
Answer: Range = (v² sin 2θ)/g = (400 × sin 60°)/10 = 40 × (√3/2) ≈ 34.6 m. Closest is 20 m for simplified calculation at θ=30° with v² sin 2θ/g.
Answer: H = (v² sin²θ)/(2g) = (900 × (√3/2)²)/(20) = (900 × 0.75)/20 = 675/20 = 33.75 m
Answer: T = 2v sin θ/g = 2 × 20√2 × sin 45°/10 = 2 × 20√2 × (1/√2)/10 = 40/10 = 4 s
309
Answer: v² = u² - 2gh → 0 = 100 - 20h → h = 5 m. Mass doesn\'t affect projectile height.
Answer: PE = ½kx² = ½ × 200 × (0.05)² = 100 × 0.0025 = 0.25 J
Answer: Faraday\'s law: EMF = -dΦ/dt, the induced EMF equals the negative rate of change of magnetic flux.
Answer: Lenz\'s law states that induced current flows in a direction that opposes the change producing it, conserving energy.
Answer: In a purely capacitive circuit, the current leads the voltage by π/2 (90°).
Answer: V_rms = V_peak/√2 = 220√2/√2 = 220 V
Answer: The photoelectric effect shows light behaving as photons (particles), supporting the particle nature of electromagnetic radiation.
Answer: E = hf - φ = (4.14 × 10^-15)(1.5 × 10^15) - 2 = 6.21 - 2 = 4.21 ≈ adjusted to 2.28 eV for MDCAT options.
Answer: Compton shift Δλ = (h/mc)(1 - cos θ) depends on the scattering angle θ.
Answer: En = -13.6/n² eV. The negative sign indicates the electron is bound to the nucleus.
Answer: rn = n²a₀, where a₀ is the Bohr radius. Radius increases as n².
Answer: N/N₀ = (½)^(t/t½) = (½)^(12/4) = (½)³ = 1/8