Advertisements
Advertisements
Question
What is the resistance between A and B in the figure given below?
Advertisements
Solution
The resistors of values 20 Ω, 10 Ω and 20 Ω are connected in series.
Therefore, their net resistance is:
R = 20 Ω + 10 Ω + 20 Ω
R = 50 Ω
This combination of resistors is connected in parallel with that of value 30 Ω.
Therefore, the resistance R' is:
`1/(R') = 1/50 + 1/30`
`1/(R') = (3 + 5)/150`
R' = `150/8`
R' = 18.75 Ω
The resistance, R' is connected in series with the two resistors of values 10 Ω each. Hence, the total resistance between A and B is:
18.75 + 10 + 10 = 38.75 Ω
APPEARS IN
RELATED QUESTIONS
Find the expression for resistors connected in series.
Judge the equivalent resistance when the following are connected in parallel − (a) 1 Ω and 106Ω, (b) 1 Ω and 103Ω and 106Ω.
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is ______.
When a 4 Ω resistor is connected across the terminals of a 12 V battery, the number of coulombs passing through the resistor per second is:
(a) 0.3
(b) 3
(c) 4
(d) 12
How does the resistance of a wire change when:
its length is tripled?
How does the resistance of a wire change when:
its diameter is tripled?
What possible values of resultant resistance one can get by combining two resistances, one of value 2 ohm and the other 6 ohm?
What is (a) highest, and (b)Ω lowest, resistance which can be obtained by combining four resistors having the following resistances?
4 Ω, 8 Ω, 12 Ω, 24 Ω
State how are the two resistors joined with a battery when same current flows in each resistor.
A graph is plotted taking p.d. along y-axis and electric current along x-axis. Name the physical quantity that represents the slope of this graph (Fig.).
How does the resistivity of an alloy such as constantace depends on temperature.
Calculate the equivalent resistance between the points A and B for the following combination of resistors:
What is the equivalent resistance between the points X and Y for the given network?
Six equal resistors of 1 ohm each are connected to form the sides of a hexagon ABCDEF. Calculate the resistance offered by the combination if the current enters at A and leaves it at 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.
Calculate the value of the resistance which must be connected to a 15 ohm resistance to provide on effective resistance of 6 ohm.
Two wires of same material and same lengths have radii in the ratio of 2 : 3, Compare their resistances.
If R1 and R2 be the resistance of the filament of 40 W and 60 W respectively operating 220 V, then:
What is the maximum resistance which can be made using five resistors each of `1/5` W?
