Advertisements
Advertisements
प्रश्न
If two resistors of 25 Ω and 15 Ω are joined together in series and then placed in parallel with a 40 Ω resistor, the effective resistance of the combination is :
(a) 0.1 Ω
(b) 10 Ω
(c) 20 Ω
(d)40 Ω
Advertisements
उत्तर
(c) 20 Ω
When 25 Ω and 15 Ω are connected in series, then:
Total resistance, R = 25 + 15 = 40 Î
This 40 Î is connected in parallel with the 40 Î resistor.
Therefore, the net resistance = 40 / 2 = 20 Î
APPEARS IN
संबंधित प्रश्न
Find the expression for the resistors connected in series and write the two characteristics of it. (Draw figure).
A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω and 12 Ω, respectively. How much current would flow through the 12 Ω resistor?
Calculate the resistance of an aluminium cable of length 10 km and diameter 2.0 mm if the resistivity of aluminium is 27 × 10−8 Ωm.
How does the resistance of a wire change when:
its length is tripled?
The diagram below shows part of a circuit:
If this arrangement of three resistors was to be replaced by a single resistor, its resistance should be:
(a) 9 Ω
(b) 4 Ω
(c) 6 Ω
(d) 18 Ω
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
Name a substance of which the resistance remains almost unchanged by the increase in temperature.
State how are the two resistors joined with a battery when equivalent resistance is more than either of the two resistances.
Answer the following question.
While studying the dependence of potential difference ( V) across a resistor on the current (I) passing through it, in order to determine the resistance of the resistor, a student took 5 readings for different values of current and plotted a graph between V and t. He got a straight line graph passing through the origin. What does the straight-line signify? Write the method of determining the resistance of the resister using this graph.
The voltage applied to a given rheostat is made four times its initial value. By what factor will be resistance of the rheostat change?
In the circuit shown below, calculate the equivalent resistance between the points (i) A and B, (ii) C and D.
Illustrate-combination of cells e.g., three cells, in parallel, explaining the combination briefly. Obtain an expression for current ‘i’ in the combination.
Two resistors having 2Ω and 3Ω resistance are connected—(i) in series, and (ii) in parallel. Find the equivalent resistance in each case.
What is the maximum resistance which can be made using five resistors each of `1/5` W?
When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:
