1
GATE ME 1993
MCQ (Single Correct Answer)
+1
-0.3
The first law of thermodynamics takes the form $$W = - \Delta \,H$$ when applied to :
A
A closed system undergoing a reversible adiabatic process.
B
An open system undergoing an adiabatic process with negligible changes in kinetic and potential energies.
C
A closed system undergoing a reversible constant volume process.
D
A closed system undergoing a reversible constant pressure process.
2
GATE ME 1993
MCQ (Single Correct Answer)
+2
-0.6
Round the clock cooling of an apartment having a load of $$300$$ $$MJ/day$$ requires and air-conditioning plant of capacity about
A
$$1$$ ton
B
$$5$$ tons
C
$$10$$ tons
D
$$100$$ tons
3
GATE ME 1993
MCQ (Single Correct Answer)
+1
-0.3
A body of weight $$100$$ $$N$$ falls freely a vertical distance of $$50m$$.The atmospheric drag force is $$0.5N.$$ For the body, the work interaction is
A
$$+5000$$ $$J$$
B
$$-5000$$ $$J$$
C
$$-25$$ $$J$$
D
$$+25$$ $$J$$
4
GATE ME 1993
Subjective
+2
-0
A vertical cylinder with a freely floating piston contains $$0.1$$ $$kg$$ air at $$1.2$$ bar and a small electrical resistor. The resistor is wired to an external $$12$$ Volt battery. When a current of $$1.5$$ amps is passed through the resistor for $$90$$ $$secs,$$ the piston sweeps a volume of $$0.01$$ $${m^3}.$$ Assume $$(i)$$ piston and the cylinder are insulated and $$(ii)$$ air behaves as a ideal gas with $${C_v} = 700\,\,J/kg\,K.$$
Find the rise in temperature of air. GATE ME 1993 Thermodynamics - Calculation of Work and Heat Question 12 English