In a large building, there are 15 bulbs of $$40\,W,$$ 5 bulbs of $$100\,W,$$ 5 fans of $$80\,W$$ and 1 heater of $$1\,kW.$$ The voltage of electric mains is $$220\,V.$$ The minimum capacity of the main fuse of the building will be:
A.
$$8\,A$$
B.
$$10\,A$$
C.
$$12\,A$$
D.
$$14\,A$$
Answer :
$$12\,A$$
Solution :
Total power consumed by electrical appliances in the building, $${P_{total}} = 2500W$$
Watt = Volt × ampere
$$\eqalign{
& \Rightarrow 2500 = V \times I \cr
& \Rightarrow 2500 = 2201 \cr
& \Rightarrow I = \frac{{2500}}{{220}} = 11.36 \approx 12A \cr} $$
(Minimum capacity of main fuse)
Releted MCQ Question on Electrostatics and Magnetism >> Electric Current
Releted Question 1
The temperature coefficient of resistance of a wire is 0.00125 per $$^ \circ C$$ At $$300\,K,$$ its resistance is $$1\,ohm.$$ This resistance of the wire will be $$2\,ohm$$ at.
The electrostatic field due to a point charge depends on the distance $$r$$ as $$\frac{1}{{{r^2}}}.$$ Indicate which of the following quantities shows same dependence on $$r.$$
A.
Intensity of light from a point source.
B.
Electrostatic potential due to a point charge.
C.
Electrostatic potential at a distance r from the centre of a charged metallic sphere. Given $$r$$ < radius of the sphere.