Physics MCQs for NEET — Practice Questions with Answers

While not explicitly stated in the provided text for a bar magnet, the property of magnetic field lines emerging from one face and entering another is stated for a solenoid: 'The field lines remain continuous, emerging from one face of the solenoid and entering into the other face.' By analogy and general magnetic principles (which candidates for NEET are expected to know), magnetic field lines emerge from the North pole and enter the South pole outside a magnet. The provided context about iron filings also implies this pattern.

The NCERT text states: 'In Fig. 4.15(b), we see that the field at the interior mid-point P is uniform, strong and along the axis of the solenoid.' This directly supports option 2.

The NCERT text explicitly states: 'The magnetic field lines do not intersect, for if they did, the direction of the magnetic field would not be unique at the point of intersection.' Options 1, 2, and 4 are all stated as properties of magnetic field lines.

The NCERT text provides: 'In particular, we can write down the equatorial field ($B_E$) of a bar magnet at a distance r, for $r >> l$, where l is the size of the magnet: $B_E = -\frac{\mu_0}{4\pi} \frac{m}{r^3}$ (5.4).' This matches option 2.

The NCERT text states: 'Comparison of Eqs. (5.1), (5.2) and (5.3) with the corresponding equations for electric dipole (Chapter 1), suggests that magnetic field at large distances due to a bar magnet of magnetic moment m can be obtained from the equation for electric field due to an electric dipole of dipole moment p, by making the following replacements: $\vec{E} \to \vec{B}$, $\vec{p} \to \vec{m}$, $\frac{1}{4\pi\epsilon_0} \to \frac{\mu_0}{4\pi}$'. This set of replacements is correctly reflected in option 3.

The NCERT text says: 'In Fig. 4.15(a), it is clear from the circular loops that the field between two neighbouring turns vanishes.' This directly supports option 2.

The NCERT text states: 'The torque on the needle is [see Eq. (4.23)], $\vec{\tau} = \vec{m} \times \vec{B}$ (5.2). In magnitude $\tau = mB \sin\theta$. Here $\tau$ is restoring torque and $\theta$ is the angle between $m$ and $B$.' Since a solenoid acts as a bar magnet, this applies to the equivalent solenoid as well. Therefore, $\theta$ is the angle between the magnetic moment ($m$) and the magnetic field ($B$). This aligns with option 3.

According to the NCERT text, 'Heat is a form of energy that flows between a body and its surrounding medium by virtue of temperature difference between them. The degree of hotness of the body is quantitatively represented by temperature.' This clearly distinguishes heat as energy transfer due to temperature difference, and temperature as a measure of the degree of hotness.

The NCERT text states: 'The ideal gas equation connecting pressure (P), volume (V) and absolute temperature (T) is : $PV = \mu RT$'. Therefore, T represents absolute temperature, which is typically measured in Kelvin.

The text states: 'We can perceive temperature by touch. However, this temperature sense is somewhat unreliable and its range is too limited to be useful for scientific purposes.' The scenario where two objects at the same temperature feel different to touch is a classic example of this unreliability, as it depends on their thermal conductivity, not just their actual temperature.