The moderator used in a nuclear reactor serves to MCQ with Answer and Explanation

Explanation:
The formula for capacitors in series is exactly the opposite of resistors. 1/C_eq = 1/C1 + 1/C2 + 1/C3. Here, all are 3 uF. So, 1/C_eq = 1/3 + 1/3 + 1/3 = 3/3 = 1. Therefore, C_eq = 1 microfarad. When identical capacitors are in series, you simply divide the capacitance by the number of capacitors (3/3 = 1).

Explanation:
Spectrometer measures wavelengths of light using diffraction gratings or prisms to disperse light and angular measurements. Interferometer (D) can also measure wavelength but spectrometer is the standard instrument for spectral analysis. Microscope and telescope magnify images, not measure wavelength. Memory tip: 'Spectrometer = wavelength measurement via dispersion; used in spectroscopy'. This instrument-application question tests practical physics knowledge, frequently examined in competitive exams. Always associate instruments with their primary function; competitive exams often test context-specific uses.

Explanation:
The effective acceleration due to gravity at latitude lambda is g' = g - R * w^2 * cos^2(lambda), where w is angular velocity. At the equator, lambda = 0, so cos(0) = 1. This subtracts the maximum outward centrifugal acceleration (Rw^2) from g. At the poles, lambda = 90, centrifugal effect is zero. Thus, g is minimum exactly at the equator.