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
a) nichrome
b)silicon
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)
