An electric heater is rated 1500 watt. If electric power costs Rs. 2 per kilp-watt-hour, then the cost of power of 10 hours running of the heater is

Options

A. Rs. 30
B. Rs. 15
C. Rs. 150
D. Rs. 25

Explanation

To solve the problem step-by-step, we will calculate the cost of running the electric heater for 10 hours.

### Step 1: Convert the power rating from watts to kilowatts
The power rating of the electric heater is given as 1500 watts. To convert this to kilowatts, we use the conversion factor:
\[ 1 \text{ kilowatt} = 1000 \text{ watts} \]
So,
\[ \text{Power in kilowatts} = \frac{1500 \text{ watts}}{1000} = 1.5 \text{ kilowatts} \]

### Step 2: Calculate the energy consumed in kilowatt-hours
The energy consumed by the heater when it runs for a certain time can be calculated using the formula:
\[ \text{Energy (kWh)} = \text{Power (kW)} \times \text{Time (h)} \]
Here, the time is given as 10 hours. Therefore,
\[ \text{Energy consumed} = 1.5 \text{ kW} \times 10 \text{ h} = 15 \text{ kWh} \]

### Step 3: Calculate the cost of the energy consumed
The cost of electricity is given as Rs. 2 per kilowatt-hour. To find the total cost for the energy consumed, we multiply the energy consumed by the cost per kilowatt-hour:
\[ \text{Cost} = \text{Energy consumed (kWh)} \times \text{Cost per kWh} \]
Substituting the values:
\[ \text{Cost} = 15 \text{ kWh} \times 2 \text{ Rs/kWh} = 30 \text{ Rs} \]

### Final Answer
The cost of power for running the heater for 10 hours is Rs. 30.

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