Q11) The sequence of bands marked on a carbon resistor are: Red, Red, Red, Silver. Write the value of resistance with tolerance.
Q12) A wire of resistivity ρ is stretched to three times its initial length, what will be its new resistivity.
Q13) state the working principle of potentiometer explain with the help of circuit diagram how the emf of two primary cells are compared by using the potentiometer
Q14) State Kirchhoff’s law an electrical network. Using the Kirchhoff’s laws deduce the condition for balance in the Wheat-stone bridge.
Q15) A Voltmeter, an ammeter and a resistance are connected in series with a battery. There is
some deflection in voltmeter but the deflection of ammeter is zero. Explain why?
Q16)Draw a neat and labelled diagram of a cyclotron . State the underlying the principle and explain how a positively charged particle will get accelerated. Show mathematically the cyclotron frequency does not depend upon speed of the particle
Q17) With the help of a labelled diagram the underlying principle and working of a moving coil galvanometer. What is the function of
i) uniform radial field
ii) soft iron core in such a device.
Q18) . Three resistance 3Ω,6Ω and 9Ω are connected to a battery. In which of them will the power dissipation be maximum if
a) They all are connected in parallel
b) They all are connected in series Give reason
Q19) Prove that current density of a metallic conductor is directly-proportional to the speed of electrons.
Q20) . Draw a graph showing variation of resistivity with temperature for
Q21) Two long straight wires are set parallel to each other. Each carries a current I in the same
direction and the separation between them is 2r.Find the force produced. Identify its nature( mention the rule to identify)