Advertisements
Advertisements
प्रश्न
What are ohmic conductors? Give one exmaple. Draw a graph showing the current-voltage relationship for an ohmic conductor.
Advertisements
उत्तर
The conductors which obey Ohm’s law (i.e., V/I is constant) are called ohmic conductors.
Example: Silver.
A graph showing the current-voltage relationship for a ohmic conductor is shown in the figure.
संबंधित प्रश्न
Graph showing the variation of current versus voltage for a material Ga As is shown in the figure. Identify the region of
(i) negative resistance
(ii) where Ohm's law is obeyed.
Fill in the following blank with suitable words:
Resistance is measured in .............. The resistance of a wire increases as the length ..............; as the temperature ..............; and as the cross-sectional area .............. .
Calculate the electric field in a copper wire of cross-sectional area 2.0 mm2 carrying a current of 1 A.
The resistivity of copper = 1.7 × 10–8 Ω m
The filament of a bulb takes a current 100 mA when potential difference across it is 0.2 V. When the potential difference across it becomes 1.0 V, the current becomes 400 mA. Calculate the resistance of filament in each case and account for the difference.
State the limitations of Ohm’s law.
Draw a neat diagram for the verification of Ohm’s law by voltmeter-ammeter method. By another diagram show the relation between p.d. and current.
Which of the following is correct for V-I graph of a good conductor?
The slope of voltage (V) versus current (I) is called:
A student carries out an experiment and plots the V-I graph of three samples of nichrome wire with resistances R1, R2 and R3 respectively. Which of the following is true?
The circuit depicted in the figure is employed for studying Ohm’s Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes, E1 and E2. He records the readings of the ammeter and voltmeter, thereby calculating the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills tube 2.
Neglecting internal resistance of the cell use (> or < or =) to compare:
- the resistance in both the cases.
- the voltmeter readings in both the cases.
- the specific resistance in both the cases.
