The commercial unit of electrical energy is kWh. 1 kWh equals how many joules?
A. 3.6 × 10⁵ J
B. 3.6 × 10⁶ J
C. 3.6 × 10³ J
D. 3.6 × 10⁴ J
Answer: Option B
Solution (By JKSSB Mock Tests)
1 kWh = 1000 W × 3600 s = 3,600,000 J = 3.6 × 10⁶ J. This is a standard conversion. Power (watt) × time (hour) gives energy. 1 watt = 1 J/s. Remember this for electricity bills.
Explanation:
Latent heat of vaporization is the heat required to change unit mass from liquid to vapor at constant temperature (boiling point). For water, it's approximately 2260 kJ/kg. Latent heat of fusion applies to solid-liquid transition. Specific heat relates to temperature change without phase change. Thermal conductivity measures heat transfer rate through conduction. Memory aid: 'Vaporization = liquid to gas; fusion = solid to liquid'. This definition-based question tests precise terminology, crucial for thermodynamics sections in competitive exams where distractors often mix phase change terms.
No comments yet. Be the first to start the discussion!