Answer:
The maximum time for which it can be kept ON in a day is 6hours 20 minutes.
Explanation:
Given:
Rating of bulb = 100W, 60V
Cost electricity = 5/unit = 5/kWh
Number of bulbs = 10
Power dissipated in the chandilier, P = Number x rating of bulb [tex]= 10*100=1kW[/tex]
Let's assume that the bulb glows for T hours a day.
Therefore, energy consumed in a day = 1 x T = T kWh
energy consumed in a month = T x 30 = 30TkWh
Total cost = Energy consumes x cost per unit = 30T x 5 = 150T
Cost should be less than 1000,
i.e. 150T < 1000
[tex]\implies[/tex] T < [tex]\frac{1000}{150}[/tex]
[tex]\implies[/tex] T < [tex]\frac{20}{3}[/tex]
[tex]\implies[/tex] T < 6.66 hrs
[tex]\implies[/tex] T < 6hours 20 minutes
The maximum time for which it can be kept ON in a day is 6hours 20 minutes.
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