Science Group
Explore subjects and practice MCQs
7
Chapters
1,610
Total MCQs
Science Group
Answer: Resultant = √(3²+4²) = 5 N. a = F/m = 5/4 = 1.25 m/s²
Answer: v = fλ. If λ doubles and f is constant, v also doubles.
Answer: Persistence of hearing is approximately 0.1 seconds, which is why we hear continuous sound.
Answer: For an object beyond C in a concave mirror, the image is real, inverted, and diminished.
Answer: P = I²R → 10 = I² × 10 → I² = 1 → I = 1 A
Answer: Inside a long solenoid, the magnetic field is uniform and parallel to the axis.
Answer: The standard frequency of AC power supply in India is 50 Hz.
Answer: The moment of inertia of a solid sphere about its diameter is 2/5 MR²
Answer: Angular momentum is conserved when the net external torque acting on the system is zero.
Answer: g\' = g(R/(R+h))² ≈ g(1 - 2h/R) for h << R
Answer: t = √(2h/g) = √(90/10) = 3 s. Range = uₓt = 20 × 3 = 60 m
Answer: Kinetic friction is always less than static friction for the same pair of surfaces.
Answer: Torque = dL/dt, where L is angular momentum. This is analogous to F = dp/dt.
Answer: Destructive interference occurs when path difference = (n + ½)λ, where the waves are out of phase.
Answer: When an object is at C of a concave mirror, the image is also formed at C, real and inverted, same size.
Answer: KE = p²/2m → p = √(2mKE). If KE doubles, p becomes √2 times the original.
Answer: Red light has the longest wavelength (~700 nm) in the visible spectrum.
Answer: Ampere (A) is the SI base unit of electric current.
Answer: A charged particle entering a magnetic field perpendicularly experiences a force perpendicular to both v and B, causing circular motion.
Answer: Electric potential at a point is defined as the work done in bringing a unit positive charge from infinity to that point.