If any arbitrary surface encloses a dipole, then the net charge is zero because the total charge on the dipole is zero (dipole consists of two equal and opposite charges). According to Gauss's law.
\(\text {total flux }=\frac{1}{\varepsilon_0} \times \text { charge enclosed }=\frac{1}{\varepsilon_0} \times(0)=0 \Rightarrow \phi=0\)

Heat waves can be polarised because these are transverse waves, whereas sound waves cannot be polarised because these are longitudinal waves.
Transverse waves can oscillate in the direction perpendicular to the direction of its propagation but longitudinal waves like sound waves oscillate only along the direction of its propagation. So, longitudinal waves cannot be polarised.

As the train is intercepting vertical components of the earth's magnetic field.The flux linked with the changes.So, there will be an induced emf.

When the bar magnet is cut into two equal parts, as shown in the Fig. (a), P₁ behaves as N and P₂ behaves as S and magnetic moment of each part of magnet becomes \(\frac { M }{ 2 } \) . When pole P₂ is placed over pole P₁ as shown in Fig. (b), the Magnetic moment of the combination is zero i.e. \(\frac { M }{ 2 } -\frac { M }{ 2 } =0.\)

The body of the car is metallic. It provides electrostatic shielding to the person inside the car, because electric field inside the car is zero. The discharging due to lightning passes to the ground through the metallic body of the car.

No, it does not experience a torque, when it is placed along the direction of electric field

Since, slope of 1 > slope of 2
\(\therefore\) R₁ < R₂
Also, we know that resistance is directly proportional to the temperature.
Therefore, T₂ > T_1.

Torque, \(\tau \) = NBIA sin \(\theta\), where the terms have their usual meanings.

The electric fields find the atoms to netural entity.As it is known that, electrostatic fields are caused by excess charges. However there is no excess charge on the inner surface of an isolated conductor. Therefore, electrostatic  field inside a conductor is zero.

For the condition of electrostatics,the electric field lines must be normal to the surface of the conductor,otherwise there would be a non-zero component of electric field along the surface of conductor and charges could not be at rest.