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
(a) With the help of a circuit diagram, obtain the relation for the equivalent resistance of two resistances connected in parallel.
(b) In the circuit diagram shown below, find:
(i) Total resistance.
(ii) Current shown by the ammeter A

Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs:
(b) for lighting inside the rooms of the hotel?
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a parallel circuit to an identical power supply line.
(d) Which circuit would have less current in it?
Two resistors P and Q of the same material and length but of different thickness are connected in parallel to a battery. The cross- sectional area of P is twice that of Q. What is the ratio of
(a) The resistance of P to the resistance of Q?
(b) The current in P to the current in Q?
Find the effective resistance in the following circuit diagrams (Fig.):

What would be the danger involved in replacing a blown fuse with the one which would carry a large current?
What is meant by internal resistance of a cell?
An electrical appliance is rated at 1000 KVA, 220V. If the appliance is operated for 2 hours, calculate the energy consumed by the appliance in: (i) kWh (ii) joule.
Define an electric current.
