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​A house is supplied electricity through a 15 A fuse. The number of 100 W lamps that can be used simultaneously along with a 2KW AC is: (The AC and la
Question

​A house is supplied electricity through a 15 A fuse. The number of 100 W lamps that can be used simultaneously along with a 2KW AC is: (The AC and lamps both are rated for 220 V Supply)​

A.

​23​

B.

​18​

C.

​15​

D.

​13​

Correct option is D

The correct answer is (D) 13.

  • Electric Power:
  • The rate at which energy is converted into an electrical circuit or work is completed is known as electric power. To put it another way, it is a measure of how much energy is used over a time period.
  • The formula for electric power is given by P=VI where V is the potential difference in the circuit and P is the power.
  • I is the current of electricity.
  • Power can also be written as P=I2R and P= V2R\frac{V^2}R
  • Ohm's law is used to get the above two expressions, where voltage, current, and resistance are related in the following way: V=IR

1.Calculate the current drawn by the AC:

  • Power of AC (P) = 2 kW = 2000 W
  • Voltage (V) = 220 V
  • Current (I) =PV=2000W220V\frac{ P} V = \frac{2000 W}{220 V}​ ≈ 9.09 A

2. Calculate the maximum current available for lamps:

  • Fuse rating = 15 A
  • Current for AC = 9.09 A
  • Maximum current for lamps = 15 A - 9.09 A ≈ 5.91 A

3. Calculate the current drawn by each lamp:

  • Power of each lamp (P) = 100 W
  • Voltage (V) = 220 V
  • Current per lamp (I) = PV=100W220V\frac{P } V = \frac{100 W }{ 220 V}​ ≈ 0.45 A

4. Calculate the maximum number of lamps:

  • Maximum current for lamps = 5.91 A
  • Current per lamp = 0.45 A
  • Maximum number of lamps = 5.91A0.45A\frac{5.91 A} {0.45 A}​ ≈ 13.13

Since we can't have a fraction of a lamp, the maximum number of 100 W lamps that can be used simultaneously with the 2 kW AC is 13.

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