Two electric lamps are rated as 200 V 100w and 220v 40w respectively. Calculate electrical resistance

 Two electric lamps are rated as 200 V 100w and 220v 40w respectively. Calculate electrical resistance

 

Well, we can solve this question in two ways. That is, we can calculate resistance in two ways. I am going to tell you both these ways. Let me first mention the symbols here.

P = Power

V = Voltage

I = Current

R = Resistance

 Ok guys Now we move forward.

First Way ==>

  (A)        Voltage of first lamp (V) = 200 V

               Power of first lamp (P) = 100 W

As we all know that ====>

 

      power = voltage x current (P = V X I) ----------- (EQ 1)

To find out the resistance of the lamp, we must first know how much the current of this lamp is. If we know the current of the lamp, then we can easily find the resistance of this lamp.

Because according to Ohm's Law we have to do this. I will tell you in this question what is the interpretation of Ohm's Law. So we take EQ 1.

     P = V X I

So in this way we can say that

 

I = P / V ---------------------- (EQ 2)

 We have given values ​​of P and V, we have to put this value in EQ 2.

 

I = 100/200

I = 0.5 A

Now we have come to know the current of this lamp. Now we will remove the resistance by applying the formula of Ohm's Law. But before that you should know what is Ohm's Law. Let me tell you a very simple explanation of Ohm's Law, you will never forget it in life. The electric current of any circuit is always directly proportional to its voltage and inversely proportional to its resistance. Now we will calculate the resistance by applying Ohm's Law formula.

According to Ohm's Law ---->

V = I R

R = V / I

   = 200 / 0.5

R = 400 Ω

 

(B)         Voltage (V) of the second lamp = 220 V

               Power of second lamp (P) = 40 W

As we all know that ====>

 

      power = voltage x current (P = V X I) ----------- (EQ 1)

So in this way we can say that

 I = P / V ---------------------- (EQ 2)

 We have given values ​​of P and V, we have to put this value in EQ 2.

 I = 40/220

 I = 0.181 A

Now we will also take the value of resistance by applying the formula of Ohm's Law.

 According to Ohm's Law ---->

V = I R

 R = V / I

     = 220 / 0.181

 R = 1215 Ω ≈ 1200 Ω

 

Second Way ==>

(A)         Voltage of first lamp (V) = 200 V

               Power of first lamp (P) = 100 W

 

As we all know that ====>

 power = voltage x current (P = V X I) ----------- (EQ 1)

  P = V X I ----------- (EQ 1)

 

We all know that ====>

 I = V / R

 

In this we will put the value of I as EQ 1.

 

  P = V X V / R

 

Now if we want to assume resistance ----

 

R = V X V / P

    = 200 X 200/100

 R = 400 Ω

  

(B)           Voltage (V) of the second lamp = 220 V

                 Power of second lamp (P) = 40 W

As we all know that ====>

  power = voltage x current (P = V X I) ----------- (EQ 1)

  P = V X I ----------- (EQ 1)

 

We all know that ====>

 I = V / R

 

In this we will put the value of I as EQ 1.

  P = V X V / R

 

Now if we want to assume resistance ----

 R = V X V / P

    = 220 X 220/40

 R = 1210 Ω (We can say that 1.2KΩ

                                 That's it 

Electric power, definition, units, formula with example

Series and Parallel combination of Resistance

SHARE

Ishan Kumar