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.

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.