Question

Question 18:
Two resistors, with resistances 5 Ω and 10 Ω respectively are to be connected to a battery of emf 6 V so as to obtain :
(i) minimum current flowing (ii) maximum current flowing
(a) How will you connect the resistances in each case ? .
(b) Calculate the strength of the total current in the circuit in the two cases.

Lakhmir Singh Physics Class 10

Answer 1

Answer:

a To obtain max current we will connect it in series connection whereas to obtain min.current we will connect it in parallel connection.

b the current flowing in series connection is 0.4A whereas in parallel connection is 1.8A

Answer 2

Explanation:

Resistance of first resistor = R1 = 5Ω (Given)

Resistance of second resistor =  R2 = 10Ω (Given)

Voltage = v = 6 (Given)

(a) To obtain a minimum current the two resistors should be connected in series, whereas for a maximum current they be connected parallel to each other.  

(b) In series -

Total resistance = 5+10

= 15Ω

Thus, the total current drawn = V/R

= 6/15

= 0.4amp  

In parallel -  

Total resistance R will be given as - 1/R = 1/R1 + 1/R2

1/R =1/5+1/10

1/R=3/10

R=10/3Ω

Thus, the total current drawn by the circuit = V/R

= 6/(10/3)

= 1.8 amp