HorthooZ – Kerala GK, PSC Questions & Onam Quiz

Q1 Multiple Choice Question

How does a domestic refrigerator achieve cooling inside its insulated compartment?

A By compressing air until it freezes naturally B By generating electric sparks inside the chamber C By the rapid expansion and evaporation of a liquid refrigerant in cooling coils, absorbing latent heat D By circulating liquid nitrogen directly from outside

Q2 Multiple Choice Question

What is Mayer's relation connecting the molar specific heat at constant pressure ($C_p$) and constant volume ($C_v$) for an ideal gas?

A C_v - C_p = R B C_p - C_v = R C C_p / C_v = R^2 D C_p + C_v = R

Q3 Multiple Choice Question

What is the formula for the maximum theoretical efficiency ($\eta$) of a Carnot heat engine operating between absolute temperatures $T_1$ (source) and $T_2$ (sink)?

A \eta = 1 - (T_1 / T_2) B \eta = 1 - (T_2 / T_1) C \eta = (T_1 - T_2) \times T_1 D \eta = T_2 / (T_1 - T_2)

Q4 Multiple Choice Question

According to the Work-Energy Theorem, the total work done by a net force on an object is equal to the change in its:

A Kinetic energy B Potential energy C Total momentum D Internal thermal energy

Q5 Multiple Choice Question

What fundamental physical principle is expressed by the First Law of Thermodynamics ($\Delta U = Q - W$)?

A The Law of Conservation of Energy applied to thermodynamic systems, stating that internal energy change equals heat added minus work done. B Work done is completely independent of heat transfer C Entropy of an isolated system always decreases over time D Heat can spontaneously flow from a colder body to a hotter body without work input

Q6 Multiple Choice Question

What is the term for the amount of heat energy required to change 1 kg of a solid into liquid at its melting point without any change in temperature?

A Latent heat of fusion B Specific heat capacity C Thermal conductivity D Latent heat of vaporization

Q7 Multiple Choice Question

What is the formula for the root-mean-square (RMS) speed ($v_{rms}$) of gas molecules of molar mass $M$ at absolute temperature $T$?

A v_{rms} = \sqrt{\frac{3RT}{M}} B v_{rms} = \frac{3RT}{M} C v_{rms} = \sqrt{\frac{2RT}{M}} D v_{rms} = \sqrt{\frac{8RT}{\pi M}}

Q8 Multiple Choice Question

What does the Law of Conservation of Energy state regarding the total energy of an isolated system?

A Total energy can neither be created nor destroyed; it only transforms from one form to another B Total energy increases continuously over time C Total energy decreases due to friction into zero D Potential energy always equals kinetic energy

Q9 Multiple Choice Question

What is the rate of doing work or the rate of transfer of energy, and what is its SI unit?

A Energy, measured in Joules B Pressure, measured in Pascals C Force, measured in Newtons D Power, measured in Watts (W)

Q10 Multiple Choice Question

Which law of thermodynamics states that heat cannot spontaneously flow from a colder body to a warmer body without the input of external work?

A Zeroth Law of Thermodynamics B First Law of Thermodynamics C Third Law of Thermodynamics D Second Law of Thermodynamics (Clausius statement)

Q11 Multiple Choice Question

What is the expression for the total mechanical energy ($E$) of a satellite of mass $m$ orbiting Earth (mass $M$, radius $R$) at a distance $r$ from the center?

A E = + \frac{G M m}{r} B E = - \frac{G M m}{2r} C E = - \frac{G M m}{r} D E = \frac{1}{2} \frac{G M m}{r}

Q12 Multiple Choice Question

What is the general expression for gravitational potential energy ($U$) of a body of mass $m$ at a distance $r$ from the center of Earth (mass $M$)?

A U = - m g / r B U = m g r C U = - (G M m) / r D U = (G M m) / r^2

Q13 Multiple Choice Question

According to Newton's Universal Law of Gravitation, the gravitational force between two point masses $m_1$ and $m_2$ separated by distance $r$ is:

A F = G (m_1 + m_2) / r B F = m_1 m_2 g r C F = G (m_1 m_2) / r^2 D F = G m_1 m_2 r^2

Q14 Multiple Choice Question

According to the Stefan-Boltzmann Law, the total radiant heat energy emitted per unit surface area of a black body per unit time is proportional to:

A The fourth power of its absolute thermodynamic temperature ($E = \sigma T^4$) B The cube of temperature ($T^3$) C Directly proportional to temperature itself ($T$) D The square root of absolute temperature ($T^{1/2}$)

Q15 Multiple Choice Question

What relationship does Wien's Displacement Law establish between the wavelength of maximum emission ($\lambda_{max}$) of a black body and its absolute temperature ($T$)?

A Wavelength is directly proportional to temperature squared ($\lambda \propto T^2$) B Wavelength is completely independent of temperature changes C The product of wavelength and temperature is constant ($\lambda_{max} T = b$), meaning peak wavelength is inversely proportional to temperature. D Temperature equals wavelength divided by the speed of light

Q16 Multiple Choice Question

How is the escape velocity ($v_e$) from a planet of mass $M$ and radius $R$ derived using conservation of mechanical energy?

A By equating centripetal force to gravitational force ($v_e = \sqrt{GM/R}$) B By multiplying gravitational acceleration by planet radius ($v_e = gR$) C By setting total mechanical energy (kinetic + gravitational potential) to zero at infinity, yielding $v_e = \sqrt{2GM/R}$. D By integrating velocity over constant time intervals

Q17 Multiple Choice Question

How does the acceleration due to gravity ($g$) change as you go high up above the Earth's surface or deep down into a mine?

A It decreases with height and increases with depth B It increases with height and decreases with depth C It decreases in both cases (both with altitude and depth) D It remains constant everywhere inside and outside Earth

Q18 Multiple Choice Question

Through which primary mode of heat transfer does heat reach the Earth from the Sun across the vacuum of space?

A Radiation B Conduction C Advection D Convection

Q19 Multiple Choice Question

Kepler's Second Law of Planetary Motion (Law of Areas) is a direct consequence of the conservation of which physical quantity?

A Conservation of mass B Conservation of linear momentum C Conservation of angular momentum D Conservation of total energy

Q20 Multiple Choice Question

At which temperature does water possess its maximum density and minimum volume?

A 100 degrees Celsius B -4 degrees Celsius C 4 degrees Celsius (4 °C) D 0 degrees Celsius

Work, Energy, Gravitation & Heat