Advertisements
Advertisements
प्रश्न
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.
Advertisements
उत्तर
VoltageV = 12 V
current flowing in the circuit I = 2.5 mA = 2.5 × 10−3 A
∴ Resistance (R) = `"V"/"I"`
= `12/(2.5 xx 10^-3)`
R = `(12 xx 10^3)/25`
R = 4800 Ω
R = `4800/1000` KΩ
R = 4.8 KΩ
APPEARS IN
संबंधित प्रश्न
How should the two resistances of 2 ohms each be connected so as to produce an equivalent resistance of 1 ohm?
The resistors R1, R2, R3 and R4 in the figure given below are all equal in value.
What would you expect the voltmeter A, B and C to read assuming that the connecting wires in the circuit have negligible resistance?
What is an ohmic resistor? Give one example of an ohmic resistor. Draw a graph to show its current voltage relationship. How is the resistance of the resistor determined from this graph?
A car bulb connected to a 12 volt battery draws 2 A current when glowing. What is the resistance of the filament of the bulb? Will the resistance be more same or less when the bulb is not glowing?
Calculate the current flowing through a wire of resistance 5 Ω connected to a battery of potential difference 3 V.
What length of copper wire of resistivity 1.7 × 10-8 Ω m and radius 1 mm is required so that its resistance is 2Ω?
A wire has a length of 2.0 m and a resistance of 5.0 Ω. Find the electric field existing inside the wire if it carries a current of 10 A.
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.
Tick(✓) the correct choice in the following:
Ohm's law is applicable to
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 and define Ohm’s law.
SI unit of resistance is:
State microscopic form of Ohm’s law.
Obtain the macroscopic form of Ohm’s law from its microscopic form and discuss its limitation.
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?
Which of the following is correct for V-I graph of a good conductor?
A current of 2amp flowing through a conductor produced 80 joule of heat in 10 sec. The resistance of the conductor is:-
What is meant by resistance of a conductor ? Define its SI unit.
Why should an ammeter have low resistance?
