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“Kirchhoff’s” law is preferred over Ohm’s law. Why? Can we apply Kirchhoff’s law to both a.c. and D.C.? Kirchhoff’s laws are related to certain conservation laws. Explain? “Wheatstone bridge method of determination of resistance is considered to be more accurate than the voltmeter-ammeter method”. Why? When the Wheatstone bridge most sensitive? Wheatstone bride is not suitable for measuring very low and very high resistances. Why? A meter bridge wire is called a slide wire bridge. Why? It is better to get null deflection at the middle of the wire in a meter bridge. Why? What is meant by end correction for the meter bridge? How it can be reduced? What is potentiometer? What is its principle? What is potential gradient? What is the significance of it? Why it should be small for more accurate measurement? The potentiometer wire should be long and of uniform thickness. Why? The sensitivity of potentiometer wire can be increased by increasing its length. But we are usually sat...

Heat and temperature Short questions: 1.        Distinguish between heat and temperature? 2.        Distinguish between heat and work? 3.        When two bodies A and B are brought in contact, heat flows from body B to A. Which is at higher temperature? 4.        Why is mercury used commonly  as a thermometric substance? Give two reasons. 5.        What is thermal equilibrium? Can two object not in contact ever be in thermal equillibrium? 6.        State Zeroth law of thermodynamics? Define temperature on the basis of Zeroth law  of thermodynamics? 7.        Why two objects in thermal contact come in thermal equilibrium? 8.        Which physical quantity determines the direction of flow of heat? 9.    ...

Short Answer Questions:                                                                                                                             AP 1.        How are stationary waves formed? 2.        Longitudinal waves cannot be polarized. Why? 3.        A radio station broad...

           1.    Why do we use connecting wires made of copper? 2.       A wire carrying current remains electrically neutral. Why? 3.       A large number of free electrons are present in metals. Why is there no current in the absence of electric field across it? 4.       Why do electrons acquire a steady drift velocity after applying a voltage? 5.       A wire of resistivity ρ is stretched to three times its length. What will be its new resistivity? 6.       Name any two physical parameters on which the resistivity of the material depends? 7.       Manganin and constantans are used for making standard resistors. Why? 8.       Two wires of equal length, one of copper and other manganin, have equal resistance. Which wire is thicker? 9. ...

AP Resonance tube experiment: measurement of velocity of sound Resonance is the specific response of a system which is capable of vibrating with certain frequency to an external force acting with the same frequency. The two conditions for occurring resonances are: i)                     The frequency of applied force must be equal to the natural frequency of the system. ii)                    The applied force must be in phase with the system. In resonance tube experiment we mainly use two apparatus: tuning fork and resonance tube apparatus. A tuning fork is a U shaped structure made up of steel or an alloy of the aluminum based on stem as shown in figure. The tuning fork is set in to vibration by striking into the rubber pad by holding the stem.      ...