Question

In the circuit show, the current through 8 ohm is
same before and after connecting E. The value of
E is
12V
802
1012
Ah
(1) 12 V
(3) 4 V
(2) 6 V
(4) 2 V​

Answer 1

Given that,

In the attached figure,

Resistance R₁ = 6 ohms

Resistance R₂ = 8 ohms

Resistance R₃ = 10 ohms

Voltage of the battery is 12 V

To find,

The value of E after connecting E.

Solution,

According to the question, the current is  same before and after connecting E.

Before connecting E,

Resistors 6 ohm, 8 ohms and 10 ohms are in series. The equivalent resistance is given by :

$R_s=6+8+10\\\\R_s=24\ \Omega$

In series combination, current is same for all resistors. The current through 8 ohm resistor is :

$I=\dfrac{V}{R}\\\\I=\dfrac{12}{24}\\\\I=0.5\ A$

After connecting E, current is same as before i.e. 0.5 A.

So,

$E=IR\\\\E=0.5\times 8\\\\E=4\ V$

So, the value of E is 4 volts.