Science and Pedagogy MCQ — 148 Practice Questions with Answers

Explanation

Scientific attitude includes curiosity, open-mindedness, rational inquiry and trust in evidence-based cause-effect reasoning. Belief in superstitions is contrary to this attitude because it accepts claims without scientific evidence. Hence option D is correct.

Explanation

By the work-energy theorem, the work done by a constant force over displacement s is Fs = (1/2)mv^2 for a body starting from rest. Thus v = sqrt(2Fs/m). For fixed F and s, velocity is proportional to 1/sqrt(m), so option B is correct.

Explanation

In free simple harmonic motion without damping, amplitude, period and frequency remain fixed for the oscillator. Velocity changes continuously with time and position, becoming maximum at the mean position and zero at the extremes. Therefore C is correct.

Explanation

On dilution, the conductivity of an electrolyte decreases because the number of ions per unit volume falls. Equivalent conductivity increases on dilution because the volume containing one equivalent increases and ionic interactions decrease. For KCl, the changes are therefore decrease and increase respectively, so C is correct.

Explanation

For a sinusoidal progressive mechanical wave, the energy density is one-half times the density of the medium times the square of angular frequency and the square of amplitude. Thus u = 1/2 rho omega^2 a^2. This matches option D.