 Explanation: As the ampere circuital law gives the integral line of magnetic field intensity along an imaginary closed path. We can calculate this integral on the symmetrical path and get the magnetic field (B). Thus the ampere circuital law is used to find a magnetic field. Answer: (A)  Explanation: The resistance of a conductor increases with an increase in temperature because the thermal velocity of the free electrons increases as the temperature increases. This results in an increase in the number of collisions between the free electrons. In the case of insulators, the resistance will decrease with increasing temperature. This is mainly due to the large energy gap between the different bands. Explanation: The internal resistance of the ideal voltmeter is infinity since it should not allow any current to flow through the voltmeter. Voltmeter measures the potential difference, it is connected in parallel.    Answer: (B) Reduce the speed of fast moving neutrons.  Explanation: Thus, the NAND gate is a universal gate since it can implement the AND, OR and NOT functions. Answer: The postulates of the Rutherford model of atom are:

(1) +ve charge is concentrated in the center of the atom called nucleus.
(2) Electron revolved around the nucleus in circular paths called orbits.
(3) The nucleus is much smaller in size than the atom.  Answer: The energy contained within the system associated with random motions of the particles along with the potential energies of the molecules due to their orientation. The energy due to random motion includes translational, rotational, and vibrational energy. It is represented as U. So now we can say, since internal energy is a state function and in all the processes shown above the change in internal energy from state, ‘a’ to state ‘b’ will be the same. ΔU = Q + W

Where, ΔU is the internal energy Q is the heat added to the system W is the work done by the system.

Heat is the transfer of energy from a high-temperature body to a lower-temperature one. It is also described as energy in transit since it only occurs when there is a difference in temperature between two systems. (i) In transverse waves, the displacement of the particle is perpendicular to the direction of propagation of the wave. Below is the picture which explains how waves move sideways when the particles move up and down.

Example of Transverse wave: The ripples on the surface of the water, The secondary waves of an earthquake, Electromagnetic waves, The waves on a string, Stadium or human wave, The ocean waves.

(ii) In a longitudinal wave, the displacement of the particle is parallel to the direction of the wave propagation. What you see in the picture is the wavefront progressing forward and the particles compressing and expanding in the same direction. This wave is marked by periodic compression and rarefaction zones, where the medium expands.

Example of Longitudinal wave: Sound waves in air, The primary waves of an earthquake. Answer: An electric dipole always experiences a torque when placed in uniform as well as non-uniform electric field. But in non-uniform electric field, dipole will also experience net force of attraction. So the electric dipole in non-uniform electric field experiences both torque and force. 