EASY
12th CBSE
IMPORTANT
Earn 100

The I-V characteristics of a resistor are observed to deviate from a straight line for higher values of current as shown in Figure.
Why ?

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Important Questions on Current Electricity

EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 85

Two identical slabs of given metal are joined together, in two different ways, as shown in Figure. (i) and (ii). What is the ratio of the resistances of these two combinations ?

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EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 86
A resistance R is connected across a cell, of emf ξ and internal resistance r. A potentiometer now measures the p.d., between the terminals of the cell, as V. State the expression for 'r' in terms of ξ,V and R.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 87
A parallel combination of two cells of emf's ε1 and ε2, and internal resistances, r1 and r2, is used to supply current to a load of resistance R. Write the expression for the current through the load in terms of ε1,ε2,r1 and r2.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 88
Under what condition can we draw maximum current from a secondary cell ?
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 89
Write any two factors on which the internal resistance of a cell depends.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 90
Write two factors on which the sensitivity of a potentiometer depends.
EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 91

Graph showing the variation of current versus voltage for a material GaAs is shown in the figure. Identify the region of
(i) negative resistance
(ii) where Ohm's law is obeyed.

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EASY
12th CBSE
IMPORTANT
New Simplified Physics (Vol 1) For Class 12>Chapter 3 - Current Electricity>Text Based Exercises>Q 92
Two electric bulbs P and Q have their resistances in the ratio of 1: 2. They are connected in series across a battery. Find the ratio of the power dissipation in these bulbs.