What amount of current would pass through a 10 \Omega coil if it takes 21s for the coil to just melt a lump of ice of mass 10g at 0oC if there are no heat losses? (Latent heat of fusion of ice = 336 Jg\(^{-1}\)).
A
16.00A
B
4.00 A
C
0.50A
D
0.25A
E
0.06 A
Verified Correct Answer: B.
Physical Principles & Numerical Solution
I\(^2\)Rt = mI;
I = \(\sqrt{\frac{mI}{Rt}}\)
= \(\sqrt{\frac{10 \times 336}{10 \times 21}}\)
= \(\sqrt{16}\)
= 4.0A
Source: Myschool Past Questions Archive (Record #25042)