Convert 300 degrees Fahrenheit to Kelvin. Explain the Carnot engine cycle, internal energy, and the effect of reversing current on a magnetic field.

$$
T_K = T_C + 273.15
$$
$$
T_K = 148.89 + 273.15 = 422.04 \, \text{K}
$$
The closest option is $421.88 \, \text{K}$.
*   c) $\boxed{\text{421.88 K}}$

2. The operating cycle of the Carnot engine consists of... * d) $\boxed{\text{4 processes}}$ * Explanation: The Carnot cycle consists of two isothermal processes and two adiabatic processes.

3. The sum of random distribution of Kinetic and Potential energies within a system of molecules is called...

   • c) $\boxed{\text{Internal energy}}$
   • Explanation: Internal energy is the total energy contained within a thermodynamic system, including the kinetic and potential energies of its molecules.

4. If we reverse the direction of electric current in a conductor then the direction of magnetic field will be...

   • a) $\boxed{\text{Reversed}}$
   • Explanation: According to the right-hand rule, the direction of the magnetic field produced by a current-carrying conductor is directly dependent on the direction of the current. Reversing the current reverses the magnetic field.

5. ..... of the following appliances work on the principle of mutual induction?

   • c) $\boxed{\text{Transformer}}$
   • Explanation: Transformers operate on the principle of mutual induction, where a changing magnetic field in one coil induces an electromotive force in a nearby coil.

6. A $200 \, \Omega$ resistor is connected with AC supply of $30 \, \text{volts}$ with frequency $50 \, \text{Hz}$. The power dissipation in the resistor is.

$$
P = \frac{(30 \, \text{V})^2}{200 \, \Omega} = \frac{900 \, \text{V}^2}{200 \, \Omega} = 4.5 \, \text{W}
$$
*   Note: Based on the calculation, the power dissipation is $4.5 \, \text{W}$. None of the provided options exactly match this value. However, if we assume there might be a typo in the question and the voltage was intended to be $36 \, \text{V}$, then $P = \frac{(36 \, \text{V})^2}{200 \, \Omega} = \frac{1296 \, \text{V}^2}{200 \, \Omega} = 6.48 \, \text{W}$, which matches option (a). Assuming this intended value:
*   a) $\boxed{\text{6.48 W}}$

7. The S.I unit of electrical impedance is... * b) $\boxed{\text{Ohm}}$ * Explanation: Impedance is the measure of the opposition that a circuit presents to a current when a voltage is applied. Its SI unit is the Ohm ($\Omega$), just like resistance.

8. With which one of the following elements, silicon should be doped as to give P-Type of semi conductor.

   • d) $\boxed{\text{Boron}}$
   • Explanation: P-type semiconductors are created by doping a semiconductor (like silicon) with a trivalent impurity, such as Boron, which has three valence electrons.

9. Logic gates are the basic components of the digital circuit with more than one input and...

   • b) $\boxed{\text{One output}}$
   • Explanation: Most standard logic gates (AND, OR, NOT, NAND, NOR, XOR, XNOR) have one output, regardless of the number of inputs.

10. The minimum energy that must be supplied to the electron for it to leave the metal surface is...

    • c) $\boxed{\text{Work function}}$
    • Explanation: The work function is the minimum energy (usually measured in electronvolts) required to remove an electron from the surface of a solid.

11. Astronomers cannot directly observe Black holes because. *