Advertisements
Advertisements
Question
Two cells each having an e.m.f. of 2 V and an internal resistance of 2Ω are
connected (a) In series, and ( b) In para 1le l as shown in fig. . What is the
current flowing through the cir cu it in each_ case?
Advertisements
Solution
(a) Given, emf (e) of the battery= 2 x 2 = 4V,
internal resistance r = 2 x 2= 4Ω
Resistance in the circuit, R = 4 Ω
Total resistance of the given series circuit = 4 + 4 = 8Ω
Current flowing through the circuit, I = `"e"/("R" + "r") = 4/8 =0.5 "A"`
(b) Given, emf of battery ( e) = emf of each cell in parallel = 2V,
Total internal resistance `1/"r" = 1/2 + 1/2 = 1Ω`
Resistance connected in the circuit ,R = 4Ω
Total resistance of the circuit= 1 + 4 = 5 Ω
Current flowing through the circuit, I= `"e"/("R" + "r") = 2/5 = 0.4 "A"`
APPEARS IN
RELATED QUESTIONS
Define the unit of current.
What is the unit of electric current?
Fill in the folloing blank with suitable words:
Current is measured in ............... using an ............... placed in ............... in a circuit.
If you were going to connect two light bulbs to one battery, would you use a series or a parallel arrangement? Why? Which arrangement takes more current from the battery?
A fuse is a short piece of wire of high ______ and low ______.
Define the following:
Electromotive force
What should I choose ___________________
b. for getting protection from electric current.
c. to measure the current in the circuit?
How should the electric lamps in a building be connected?
Match the items in column-I to the items in column-II:
| Column - I | Column - II | ||
| (i) | electric current | (a) | volt |
| (ii) | potential difference | (b) | ohm meter |
| (iii) | specific resistance | (c) | watt |
| (iv) | electrical power | (d) | joule |
| (v) | electrical energy | (e) | ampere |
Match the following:
| 1. | 1 mA | a. | series |
| 2. | 1 pA | b. | ohmmeter |
| 3. | Ammeter | c. | 10-6 ampere |
| 4. | Electrical resistivity | d. | 10-3 ampere |
