Physics Past Questions and Answers

What amount of current would pass through a 10 Ω 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\(^{-1}\)).

How long does it take a 750 W heater operating at full rating to raise the temperature of 1 kg of water from 40^oC to 70^oC? (Take the specific heat capacity of water as 4200 J kg^-1 K^-1 and neglect heat losses).

24 Na → 24 mg⁴ + X + energy 11 &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp2 &nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp&nbsp



The equation above represents a nuclear decay of sodium isotope. What is X?

lf Einstein’s photoelectric equation is represented by hf - W = Φ where h is Planck’s constant, f the frequency of incident radiation and W the work function of the material, what does the symbol Φ up stand for?

The phenomenon of radioactivity was first discovered by