Physics 2021 JAMB Past Questions - Question 15: A 50w heating coil is used for 2 minutes to heat a spherical metal ball of mass 0.5kg and specific heat capacity of 1,000jkg-¹ k-¹, the temperature rise is?

Correct Answer

C

Explanation

To find the temperature rise of the spherical metal ball, we can use the formula:

Q = mcΔT

Where:
Q = heat energy
m = mass of the metal ball
c = specific heat capacity of the metal
ΔT = change in temperature

First, let's calculate the heat energy produced by the heating coil:

Power (P) = 50 watts
Time (t) = 2 minutes = 120 seconds

Energy (Q) = Power × Time
Q = Pt
Q = 50 watts × 120 seconds
Q = 6000 joules

Now, we can use the formula to find the temperature rise:

6000 joules = 0.5 kg × 1000 J/kg·K × ΔT
ΔT = 6000 joules / (0.5 kg × 1000 J/kg·K)
ΔT = 12 K

So, the temperature of the spherical metal ball rises by 12 degrees Celsius.