Question

An electric lamp whose resistance is 40Ω and conductor of 8Ω resistance
are connected in series to 12V battery in an electric circuit. Calculate the
total resistance of the circuit and the current flowing through the circuit

Answer 1

Explanation

B)In series combination,R=R Lamp +R conductor=10Ω+2Ω=12ΩI= R/V

V = 12Ω/6v

6v =0.5A

6v =0.5A⇒V Lamp

6v =0.5A⇒V Lamp =IR=0.5×10=5V

Answer 2

Given :

1. Resistance of lamp is 40Ω
2. Resistance of conductor is 8Ω
3. Connected in series to 12V battery.

To find : The total resistance of the circuit and the current flowing through the circuit.

Solution :

The total resistance of the circuit is 48Ω. The current through the circuit is 0.25 A.

We can simply solve this numerical problem by using the following method. (in this case, our goal is to calculate the total Resistance of the circuit and the current through the circuit)

Now, to calculate the total resistance we have to add the resistance of lamp and conductor (which are connected in series).

So, as per series connection :

The total resistance = Resistance of electric lamp + Resistance of conductor = (40+8) Ω = 48Ω

Now, we also know that :

V = IR

Where,

• V = Voltage
• I = Current
• R = Resistance

So, by putting the given and obtained values, in the above mentioned mathematical relationship, we get :

12 = I × 48

I = 12/48

I = 0.25 A

Hence, the total resistance of the given circuit is 48Ω and the current is 0.25A