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प्रश्न
Define Current density.
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उत्तर
Current density is a vector quantity, often known as an area vector or cross-sectional area vector, whose value is equal to the electric current flowing per unit area.
J = `"I"/"A"`
S.I unit is A/m2.
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संबंधित प्रश्न
The relationship between the potential difference and the current in a conductor is stated in the form of a law.
1) Name the law.
2) What does the slope of V-I graph for a conductor represent?
3) Name the material used for making the connecting wire.
Name the law which is illustrated by the above V−I graph.
The unit of electrical resistance is:
(a) ampere
(b) volt
(c) coulomb
(d) ohm
The graph between V and I for a conductor is a straight line passing through the origin.
Which law is illustrated by such a graph?
A resistance of 40 ohms and one of 60 ohms are arranged in series across 220 volt supply. Find the heat in joules produced by this combination of resistances in half a minute.
State Ohm’s law and draw a neat labelled circuit diagram containing a battery, a key, a voltmeter, an ammeter, a rheostat and an unknown resistance to verify it.
- Draw a V-I graph for a conductor obeying Ohm’s law.
- What does the slope of V–I graph for a conductor represent?
How would you connect two resistors in series? Draw a diagram. Calculate the total equivalent resistance.
Show by a diagram how two resistors R1 and R2 are joined in parallel. Obtain an expression for the total resistance of the combination.
In the circuit shown in the figure, find the total resistance of the circuit and the current in the arm AD.
Calculate the effective resistance across AB?
Fig. represents the circuit used for the verification of ohm's law. Label the different parts from A and F. State the function of each.
Fig. represents the circuit used for the verification of Ohm's law. Label the parts from A to F. state the function of each.
State microscopic form of Ohm’s law.
Which of the following I-V graph represents ohmic conductors?
The unit of specific resistance is ____________.
A heater of 220 V heats a volume of water m 5 mint time. A heater of 110 V heat in ten second. The resistance of the conductor is
Suppose there is a circuit consisting of only resistances and batteries and we have to double (or increase it to n-times) all voltages and all resistances. Show that currents are unaltered. Do this for circuit of Example 3.7 in the NCERT Text Book for Class XII.
