plz solve this question from my board paper 2019

Asked by ramandeep.kaur | 5th Mar, 2019, 05:22: PM

Expert Answer:

V = 3.3 V 
 
Internal resistance = 0.5 Ω
 
1. The resistance of circuit when key k is open
 
The resistance of 5 ohms and internal resistance of 0.5 ohms will be considered:
 
So, R = 5 + 0.5 = 5.5 Ω
 
2. The current drawn from the cell when key k is open
 
Current drawn will be 
 
I = V/R = 3.3/ 5.5  =0.6 A 
 
3. The resistance of circuit when key k is closed 
 
Resistors in series are 2 ohms and 3 ohms
 
So, R = 2 + 3 = 5 ohms 
 
Resistance in parallel,
 
1 over R subscript p space equals space 1 over R subscript 1 plus 1 over R subscript 2 space equals space 1 fifth plus 1 fifth space equals space 2 over 5

rightwards double arrow space R subscript p space end subscript space equals space 2.5 space capital omega space
R space equals space 2.5 space plus 0.5 space equals space 3 space capital omega
 
4. The current in the circuit when key k is closed 
 
Total current = Total voltage/ Resistance = 3.3/3 = 1.1 Ω

Answered by Shiwani Sawant | 5th Mar, 2019, 06:25: PM