Advertisements
Advertisements
Question
Three resistors of 6Ω, 3Ω and 2Ω are connected together so that their total resistance is greater than 6Ω but less than 8Ω Draw a diagram to show this arrangement and calculate its total resistance.
Advertisements
Solution
We connect the resistance of 3 Ω and 2 Ω in parallel to each other and then connect this (parallel combination) to the 6 Ω resistance in series. The required arrangement is as shown in given figure. The equivalent resistance of 3Ω and 2 Ω in parallel.
`1/"R" = 1/3 + 1/2 = (2 + 3)/6 = 5/6`
or R = `6/5`Ω = 1.2 Ω
Thus, the total resistance of the set up is (1.2 + 6) Ω = 7.2 Ω
RELATED QUESTIONS
What possible values of resultant resistance one can get by combining two resistances, one of value 2 ohm and the other 6 ohm?
Name the material of wire used for making standard resistances. Give a reason.
What material is used for making wire to prepare heating coils? Give a reason.
How does the resistivity of a semiconductor depend on temperature?
State and explain the laws of resistance.
You are provided with three resistors of resistance 1.0 Ω, 2.0 Ω and 3.0 Ω How would you connect them to obtain the total effective resistance 1.5 Ω? Draw diagram of the arrangement and check it by calculations.
In the circuit shown below, calculate the equivalent resistance between the points (i) A and B, (ii) C and D.
Two lamps of resistance 30Ω and 20Ω respectively are connected in series in a 110V circuit. Calculate:
(i) the total resistance in the circuit
(ii) the current in the circuit, and
(iii) the voltage drop across each lamp.
What should be the length of a nickel wire of area of cross-section 3 mm2 used for making a rheostat of 750 ohm? (ρ of nickle = 0.069 Ohm mm2/m)
The resistance of the hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamps, when not in use?
