Answer:
Heat dissipated, H = 1440 Joules
Step-by-step explanation:
It is given that,
Resistor 1,
Resistor 2,
Voltage, V = 10 volts
Both resistors are connected in series. The equivalent resistance is given by :

R = 30 + 20
R = 50 ohms
In series combination, the current throughout the circuit remains the same. It can be calculated using ohm's law as :
V = IR
I = 0.2 A
Heat dissipated in R2 during (1/2) h, t = 1800 s is given by :
H = 1440 J
So, the heat dissipated during 1800 seconds is 1440 Joules. Hence, this is the required solution.