Junior Inter Physics Questions and Answers
1. What are fundamental forces in nature?
Ans: There are four fundamental forces in nature. They are used to study microscopic and macroscopic properties. They are
1) Gravitational force
2) Electromagnetic force
3) Strong nuclear force
4) Weak nuclear force
2. What is the discovery of C.V. Raman?
Ans: C.V. Raman discovered ”Raman effect” (inelastic scattering of light by molecules) and received Nobel Prize for it.
3. Distinguish between accuracy and precision?
Ans: Accuracy: The closeness of measured value to the true value of quantity is called accuracy.
If smaller is the value of error larger will be accuracy.
Precision: The limit (or) resolution of the quantity measured with given instrument is called precision. If smaller the value of least count, larger the value of precision.
4. What are theoretical and practical limits of Poissions ratio?
Ans: Theoretical limits of Poissions ratio are -1 to 0.5 and practical limits are 0 to 0.5.
5. What is the period of revolution of geostationary satellite. Does it rotate from west to east (or) east to west?
Ans: The period of revolution of geostationary satellite is 24 hours. It revolves round the earth at a constant speed once per day over equator from west to east.
6. Hot liquids flow faster than cold liquids. Explain.
Ans: In liquids as temperature increases, cohesive forces decreases and therefore the viscosity of liquids decreases.
7. What is Magnus effect?
Ans: The dynamic lift due to spinning is called Magnus effect.
8. What is specific heat of a gas in (a) an isothermal change (b) an adiabatic change?
Ans: Specific heat of gas in an isothermal change is infinity. In adiabatic change is zero.
9. State conditions under which Newton’s law of cooling is applicable.
❊ Loss of heat is negligible by conduction. Heat lost is mainly by convection.
❊ Loss of heat occurs in streamlined flow of air.
❊ Temperature of body is uniformly distributed over it.
10. Define thermal equilibrium. How does it leads to Zeroth Law of thermodynamics?
Ans: Any state of system in which thermodynamic co-ordinates (P, V, T) remain unchanged is called thermal equilibrium.
Zeroth Law: If two systems are in thermal equilibrium with a third system separately then they are in thermal equilibrium with each other. It leads the concept of temperature.
TA = TC, TB = TC
⇒ TA = TB