Physics

The coefficient of viscosity (dynamic viscosity) in SI units is expressed as Pascal-second (Pa·s), which is equivalent to kg·m⁻¹·s⁻¹. Option B correctly represents this unit.

Option C, S = Vt2, is dimensionally incorrect because displacement (S) has dimensions of length [L], velocity (V) has dimensions [L T^-1], and time squared (t^2) has dimensions [T^2]. Multiplying velocity by time squared gives dimensions [L T^-1][T^2] = [L T], which is not length. The correct kinematic equation is S = Vt or S = 1/2 at^2, both dimensionally consistent.

The curie (Ci) is defined as 3.7 × 10^10 disintegrations per second, which is the standard unit of radioactivity. Option A is the closest and correctly formatted value (3.74 × 10^9 is a typo and should be 3.7 × 10^10). The other options have incorrect values or exponents.

A self-sustained nuclear reaction where neutrons from one fission event cause further fission events is called a chain reaction. This is fundamental to how nuclear reactors and atomic bombs operate.

The angle between two vectors A and B can be determined using their dot product formula: A · B = |A||B|cosθ, where θ is the angle between the vectors. This relationship allows calculation of the angle by rearranging to θ = cos⁻¹((A · B)/(|A||B|)).

When one atom of U-235 undergoes fission, approximately 200 MeV of energy is released due to the splitting of the nucleus into smaller fragments and the release of neutrons and gamma radiation.

Radioactive materials are identified by measuring their half-life, which is the time it takes for half of the radioactive atoms to decay. This property is unique to each radioactive isotope and helps in their identification.

Chlorofluorocarbons (CFCs) have been widely used in refrigeration, aerosol sprays, and the plastic foam industry due to their stability and non-flammability. Therefore, all the options listed are correct uses of CFCs.

Strontium-90 is a radioactive isotope that primarily emits beta (β) particles during its decay process, making it a beta-particle source rather than an alpha, gamma, or neutron source.

The prefix 'pico' denotes a factor of 10 to the power of -12, which means one pico equals 10^-12 of the unit.