Question

A hot plate of an electric oven connected to a 220v line has two resistance coil A and B each of 24ohms resistance,which may be used separately in series or parallel.where are the current in all the cases

Answer 1

Solution:

Supply voltage, V = 220 V

Here Resistance of one coil, R =24 Ω


(i) Coils are used separately

According to Ohm’s law, V=I1R1

 I1 is the current flowing through the coil

I1=V/R1=220/24=9.166A

∴ current flow through the coil when used separately is 9.16 A.

 (ii) Coils are connected in series

R2=24 Ω+24 Ω=48 Ω

According to Ohm’s law

I2=V/R2=220/48=4.58A

the current flowing through the series circuit is 4.58A

(iii) Coils are connected in parallel





According to Ohm’s law

I3=V/R3=220/12=18.33A

the current flowing through the parallel circuit is 18.33A

Answer 2

Case I: 9.17 Amperes

Case II: 4.58 Amperes

Case III: 18.33 Amperes

Step-by-step explanation:

Given:

Voltage(V) = 220 Volts

Resistance of Coil A, Ra = 24 ohm

Resistance of Coil B, Rb = 24 ohm

Case I: When coils are used separately.

Applying the formula,

$\fbox{V = IR}$

We get,

$I = \frac{V}{R}$

$I = \frac{220}{24} = 9.17 A$

Therefore, the current flowing in this circuit is 9.17 Amperes.

Case II: When coils are used in series.

Equivalent Resistance,

R = 24 + 24 = 48 ohms

Applying Formula V = IR,

$I = \frac{V}{R}$

$I = \frac{220}{48} = 4.58A$

Therefore the current flowing  is 4.58 Amperes.

Case III: When coils are used in parallel.

Equivalent Resistance,

$R = \frac{R1R2}{R1 + R2}$

$R = \frac{24 * 24}{24 + 24}$

$R = \frac{576}{48} = 12 Ohms$

Current Flowing,

$I = \frac{V}{R}$

$I = \frac{220}{12} = 18.33A$

Therefore, the current flowing is 18.33 Amperes.