NEET Practice Questions (MCQs) with Answers & Solutions

The context clearly states, 'So, as in the case of an inductor, the average power $P_C = \frac{1}{2} i_m v_m \langle \sin(2\omega t) \rangle = 0$ since $\langle \sin(2\omega t) \rangle = 0$ over a complete cycle.' (Equation 7.19 and accompanying text). Also, point 4 under summary confirms 'the average power supplied to a capacitor over one complete cycle is zero.'.

The text explains, 'When a capacitor is connected to a voltage source in a dc circuit, current will flow for the short time required to charge the capacitor. As charge accumulates on the capacitor plates, the voltage across them increases, opposing the current. ... When the capacitor is fully charged, the current in the circuit falls to zero.' (page 184).

Example 7.3 discusses this scenario: 'Reducing C will increase reactance and the lamp will shine less brightly than before.' This is because $X_C = 1/\omega C$. If C decreases, $X_C$ increases, which reduces the current ($i_m = v_m / X_C$), leading to less brightness.

The context states, 'where the amplitude of the oscillating current is $i_m = \omega C v_m$.' (page 184).

Point 7 under 'POINTS TO PONDER' (page 199) clarifies: 'There are no power losses associated with pure capacitances and pure inductances in an ac circuit. The only element that dissipates energy in an ac circuit is the resistive element.'

Figure 7.8(a) and the accompanying description clearly state: 'Here the current phasor I is $\pi/2$ ahead of the voltage phasor V as they rotate counterclockwise.' This aligns with the mathematical derivation that current leads voltage by $\pi/2$.

According to the NCERT text, 'Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism.'

The NCERT states, 'Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus'. Living phytoplankton are producers, not dead remains.

The NCERT explicitly states that humus 'undergoes decomposition at an extremely slow rate', making option 3 incorrect.

The NCERT defines mineralisation as 'the humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralisation'.