Question

suppose a 6 volt battery is connected across a lamp whose resistance is 20 ohm through a variable resistor if the current in the circuit is 0.25A calculate the value of resistance from resistor

Answer 1

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Answer 2

Answer:

The value of resistance from the resistor is 4Ω.

Explanation:

We will use the following relation of Ohms law,

$I=\frac{V_T}{R_T}$         (1)

Where,

I=current through the circuit

$V_T$=total voltage across the circuit

$R_T$=total resistance of the circuit

From the question we have,

$V_T$=6 volt

R₁=20Ω

I=0.25 A

The total resistance is given as,

$R_T=R+20$      (2)

By substituting the required values in equation (1) we get;

$0.25=\frac{6}{R+20}$         (3)

$R+20=\frac{6}{0.25}$

$R+20=24$

$R=24-20=4\Omega$

Hence, the value of resistance from the resistor is 4Ω.