A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be
A.
four times
B.
doubled
C.
halved
D.
one fourth
Answer :
doubled
Solution :
$$H = \frac{{{V^2}t}}{R}$$
Resistance of half the coil = $$\frac{R}{2}$$
∴ As $$R$$ reduces to half, $$'H'$$ will be doubled.
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.