FBISE Class 9th (SSC-l)
Explore subjects and practice MCQs
3
Chapters
1,610
Total MCQs
FBISE Class 9th (SSC-l)
Answer: Normal incidence means the ray is perpendicular to the surface, so angle of incidence = 0°
Answer: A concave lens is a diverging lens and has negative power.
Answer: Doubling back halves the length and doubles the cross-section → R becomes R/4 = 10/4 = 2.5 Ω
264
Answer: R = ρL/A. If L→2L and A→A/2, new R = ρ(2L)/(A/2) = 4ρL/A = 4R
Answer: C = ε₀A/d. If d is doubled, C becomes half.
Answer: Dipole moment p = q × d, where d is the distance between the charges.
Answer: Total internal reflection occurs when light travels from a denser to a rarer medium at an angle greater than the critical angle.
Answer: R = 2f = 2 × 20 = 40 cm
Answer: Three geostationary satellites, spaced 120° apart, can cover most of the Earth\'s surface.
Answer: The sky appears blue due to Rayleigh scattering of sunlight by atmospheric molecules, which scatter shorter (blue) wavelengths more.
Answer: By energy conservation: mgh = ½mv² → v = √(2gh) = √(2×10×3) = √60 m/s
272
Answer: F = mv²/r = 2 × 36/4 = 72/4 = 18 N
Answer: In an adiabatic process, there is no heat exchange (Q = 0) between the system and surroundings.
Answer: For an ideal gas, internal energy is a function of temperature only (U = f(T)).
Answer: η = 1 - T₂/T₁ = 1 - 300/500 = 1 - 0.6 = 0.4 = 40%
Answer: Frequency is measured in Hertz (Hz), where 1 Hz = 1 cycle per second
Answer: Component along plane = W sin θ = W sin 30° = W × ½ = W/2
Answer: By Archimedes\' principle, buoyant force equals the weight of the fluid displaced by the body.
Answer: In series combination, the same current flows through all resistors.
Answer: Centripetal force is always perpendicular to the velocity, so work = Fd cos 90° = 0