Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Available resistances = 220 Ω, 79 Ω 92 Ω
Case I:
If 3 resistors are connected in series, then
RS = R1 + R2 + R3 = 220 + 79 + 92 = 391
This value is greater than the required resistance so it is not possible.
Case II:
If 3 resistors are connected in parallel, then
`1/"R"_"p" = 1/"R"_1 + 1/"R"_2 + 1/"R"_3`
`1/"R"_"p" = 1/220 + 1/79 + 1/92` = 0.0279
Rp = 35.84 This does not meet the requirement.
Case III:
If R1 and R2 are connected in parallel and R3 in series
`1/"R"_"p" = 1/"R"_1 + 1/"R"_2 = 1/220 + 1/79 = 0.0172`
`=> "R"_"p" = 58.14 Omega`
This meets the requirement.
APPEARS IN
संबंधित 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.
The unit of electrical resistance is:
(a) ampere
(b) volt
(c) coulomb
(d) ohm
How would you connect two resistors in series? Draw a diagram. Calculate the total equivalent resistance.
In the circuit shown in the figure, find the total resistance of the circuit and the current in the arm AD.

Tick(✓) the correct choice in the following:
Ohm's law is applicable to
Ohm’s law states the relationship between power and voltage.
What is ohmic device?
The slope of voltage (V) versus current (I) is called:

Two conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 1 mm. Conductor B is a hollow tube of outer diameter 2 mm and inner diameter 1 mm. Find the ratio of resistance RA to RB.
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.
