NEET Practice Questions (MCQs) with Answers & Solutions

The NCERT states, 'Their morphological and anatomical features are greatly simplified while emphasising their reproductive potential.'

The NCERT explains, 'During the course of evolution, the eggs of the parasitic bird have evolved to resemble the host’s egg in size and colour to reduce the chances of the host bird detecting the foreign eggs and ejecting them from the nest.'

The NCERT text shows the derivation and final formula: 'Total amount of work done in establishing the current I is $W = \int dW = \int_0^I L I' dI' = \frac{1}{2} L I^2$.' (Equation 6.17).

From Example 6.9 (a) and (b), the total magnetic energy is $U_B = \frac{1}{2} L I^2$. The magnetic energy per unit volume is $u_B = \frac{U_B}{V} = \frac{U_B}{Al}$ (where V is the volume of the solenoid, $Al$). So, $u_B = \frac{1}{2} L I^2 / (Al)$. This is explicitly shown in the derivation for $u_B$ to reach $\frac{B^2}{2\mu_0}$.

The NCERT text explains this clearly: 'L is analogous to m (i.e., L is electrical inertia and opposes growth and decay of current in the circuit).' This highlights L's role as a measure of electrical inertia.

The formula derived is $u_B = \frac{B^2}{2\mu_0}$. This implies that the magnetic energy per unit volume depends solely on the magnetic field B and the permeability of free space $\mu_0$ (assuming a vacuum core or air core solenoid). Although B itself depends on current and solenoid properties, the question asks what $u_B$ depends on directly from the given formula.

The NCERT text explicitly states: 'If we ignore the resistive losses and consider only inductive effect, then using Eq. (6.14), $\frac{dW}{dt} = I L \frac{dI}{dt}$.' The subsequent integration to find W leads to $W = \frac{1}{2} L I^2$. Therefore, this expression assumes negligible resistive losses.

According to Table 3.4 'Notation for IUPAC nomenclature of Elements', the numerical root for the digit '5' is 'pent'.

For Z=108: un (1), nil (0), oct (8), and 'ium' suffix, making it Unniloctium. Let's check others: Z=109 is Unnilennium (not Ununennium), Z=106 is Unnilhexium (not Unnilseptium), Z=111 is Unununnium (not Ununbium).

The NCERT text states: 'To avoid such problems, the IUPAC has made recommendation that until a new element’s discovery is proved, and its name is officially recognised, a systematic nomenclature be derived directly from the atomic number of the element...'. This directly addresses the issue of conflicting claims, such as the American and Soviet claims for element 104.