# ICAR NET (UG/PG): Physics MCQs (Practice_Test 1 of 35)

- The Farenheit and the Centrigrade scales have the same numerical value at a temperature of
- -30 degrees
- -40 degrees
- -100degrees
- -273degrees

- van der Waals ′ equation of state of a gas takes into account
- the intermolecular forces only
- the size of the molecule only
- both the intermolecular forces and the size of the molecule
- the velocity of the molecules only

- The First Law of Thermodynamics, U = ? Q-? W indicates that when a system goes from its initial state to a final state
- ? U is the same for the every path
- ? Q is the same for every path
- ? W is the same for every path
- ? U and? Q are the same for every path

- Which one of the following properties of a body remains constant during a reversible adiabatic process?
- Enthalpy
- Temperature
- Specific heat
- Entropy

- A heat engine work on a Carnot cycle with the heat sink at a temperature of 27 degrees C. If the efficiency is 20 % , then the temperature (in Kelvin) of the heat source will be
- 375 degrees
- 300 degrees
- 270 degrees
- 150 degrees

- Which one of the following figures correctly represents the temperature (T) -entropy (S) diagram (T in absolute scale) of a Carnot cycle?
- A
- B
- C
- D

- Given that H = the enthalpy of a system T = absolute temperature and S = entropy G = H-TS is the Gibbs function for the system. In the case of a reversible, isothermal, isobaric process
- G = constant
- G > 0 and changes with T
- G < 0 and changes with S
- G changes with both T and S

- Maxwell՚s law of distribution of velocities shows that
- all particles have the same velocity
- all velocities are equally probable
- the particles have varying energies depending on their speeds
- all particles have the same energy but different velocities

- A molecular is at temperature T (in Kelvin) . According to the theorem of equi-partition of energy, the energy associated with each degree of freedom is
- KBT
- KBT
- KBT
- KBT

- If the temperature of a black body is increased, then the maximum of the spectrum will
- shift towards shorter wavelength
- shift towards shorter frequency
- shift towards the shorter or longer wavelength depending on the nature of the black body
- not shift

- If two particles of same mass having charges + q and + 9q, are allowed to fall from rest through the same electric potential difference, then their speeds will be in the ratio of
- 3: 1
- 1: 3
- 1: 9
- 9: 1

- In the circuit shown in the above figure, the charge on capacitor C3 will be
- 1.7 m coulomb
- 1.5 m coulomb
- 2.5 m coulomb
- 5 m coulomb

- Liquid dielectrics having polar molecules, such as water, always have dielectric constants that
- increase with decreasing temperature
- increase with increasing temperature
- decrease with decreasing temperature
- are independent of temperature

- A parallel plate capacitor is connected to a battery. Consider the following statements in this regard: If a metal sheet of negligible thickness is placed parallel to the plates of the capacitor
- the battery will supply more charge
- the capacitance will increase
- the potential difference between the plates will increase
- equal and opposite charges will appear on the two faces of the metal plate

Which of the above statement (s) is/are correct?

- 1 alone
- 4 alone
- 1 and 2
- 2 and 3