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
Find the resistance of a conductor if 0.24 A current is passing through it and a potential difference of 24 V is applied across it.
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.
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
Name the unit of electrical resistance and give its symbol.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Calculate the value of the resistance of the resistor.
The graph between V and I for a conductor is a straight line passing through the origin.
What should remain constant in a statement of this law?
- Draw a V-I graph for a conductor obeying Ohm’s law.
- What does the slope of V–I graph for a conductor represent?
A wire of resistance 3 ohm and length 10 cm is stretched to length 30 cm. Assuming that it has a uniform cross section, what will be its new resistance?
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.
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.
An ammeter placed in series with an electric radiator reads 0.5 amps and a voltmeter placed across it reads 230 volts. What is the resistance of the radiator?
Ohm’s law states the relationship between power and voltage.
Explain the equivalent resistance of a series resistor network.
Explain the equivalent resistance of a parallel resistor network.
Two cells each of 5V are connected in series across an 8Ω resistor and three parallel resistors of 4Ω, 6Ω, and 12Ω. Draw a circuit diagram for the above arrangement. Calculate
- the current drawn from the cell
- current through each resistor
Which of the following I-V graph represents ohmic conductors?
The temperature of a conductor is increased. The graph best showing the variation of its resistance is:
You are provided with a resistor, a key, an ammeter, a voltmeter, four cells of 1.5 V each and few connecting wires. Using circuit components, draw a labelled circuit diagram to show the setup to study Ohm's law.
State the relationship between potential difference (V) across the resistor and the current (I) flowing through it. Also draw V-I graph, taking V on the X-axis.
Let the resistance of an electrical device remain constant, while the potential difference across its two ends decreases to one fourth of its initial value. What change will occur in the current through it? State the law which helps us in solving the above stated question.
A current of 3.2 mA flows through a conductor. If charge on an electron is −1.6 × 10-19 coulomb, find the number of electrons that will pass each second through the cross section of that conductor.
