Advertisements
Advertisements
प्रश्न
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?
विकल्प
R1 = R2 = R3
R1 > R2 > R3
R3 > R2 > R1
R2 > R3 > R1
Advertisements
उत्तर
R3 > R2 > R1
Explanation -
Since the current (I) is plotted on y-axis and potential difference (V) is plotted on x-axis, so the slope of the graph is `1/"R"`. It means higher the slope, the lesser is the resistance. So, R1 will be minimum and R3 will be maximum.
APPEARS IN
संबंधित प्रश्न
An electrical bulb is marked 200V, 100W. Calculate the electrical resistance of its filament. If five such
bulbs are connected in series to a 200V supply, how much current will flow through them?
Name the law which is illustrated by the above V−I graph.
Keeping the p.d. constant, the resistance of a circuit is halved. The current will become:
(a) one-fourth
(b) four time
(c) half
(d) double
Four resistances of 16 ohms each are connected in parallel. Four such combinations are connected in series. What is the total resistance?
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.
In a conductor 6.25 × `10^16` electrons flow from its end A to B in 2 s. Find the current flowing through the conductor (e = 1.6 × `10^-19` C)
A metal sphere is kept on an insulting stands. A negatively charged rod is brought near it, then the sphere is earthed as shown. On removing the earthing, and taking the negatively charged rod away, what will be the nature of charge on the sphere? Give reason for your answer.
Define the following:
Coulomb
- Name and state the law which relates the potential difference and current in a conductor.
- What is the necessary condition for a conductor to obey the law named above in part (a) ?
What are ohmic conductors? Give one exmaple. Draw a graph showing the current-voltage relationship for an ohmic conductor.
What are non-ohmic conductors? Give one exmaple. Draw a current-voltage graph for a non-ohmic conductor.
State microscopic form of Ohm’s law.
Define temperature coefficient of resistance.
Explain the equivalent resistance of a parallel resistor network.
An electronics hobbyist is building a radio which requires 150 Ω in her circuit, but she has only 220 Ω, 79 Ω, and 92 Ω resistors available. How can she connect the available resistors to get the desired value of resistance?
Calculate the total resistance of the circuit and find the total current in the circuit.
What is meant by resistance of a conductor ? Define its SI unit.
A current of 0.8 A flows in a conductor of 40 Ω for 1 minute. The heat produced in the conductor will be ______.
