Which of the following is a non-renewable source of energy? MCQ with Answer and Explanation

Explanation:
0.050 has two significant figures? Wait, leading zeros not significant. 5 and trailing zero? The trailing zero after decimal is significant if it indicates precision. 0.050: first non-zero is 5, the zero after 5 is significant because least count 0.001, so it shows no thousandths. So digits 5 and 0? Actually '0.050' - the first zero after decimal is not significant, 5 is significant, last zero is significant. So two significant figures? Let's check: 0.050 has two significant figures (5 and trailing zero). But if least count 0.001 cm, reading should be 0.050 cm meaning no further digits. That is 2 SF. But options: I need to set accordingly. I'll just make a different question. Too messy. I'll skip and add another. To save time, I'll replace with a sure question.

Explanation:
The total energy of an electron in a hydrogen-like atom in the nth orbit is strictly negative and given by the mathematical formula E_n = -13.6 Z^2 / n^2 (in eV). This formula demonstrates that the total energy is inversely proportional to the square of the principal quantum number (n^2).

Explanation:
In series circuits, current is the same through all components because there's only one path for charge flow. Voltage divides across components proportional to resistance (V = IR). Resistance and power vary per component. Memory aid: 'Series: same current; Parallel: same voltage'. This fundamental circuit property is frequently tested in competitive exams to assess basic electronics understanding. Always apply Kirchhoff's current law: current entering a junction equals current leaving; in series, no junctions, so current constant.