Total resistance Rₜ = 21Ω + 4Ω = 25Ω. Using V = IR = 0.2 × 25 = 5V. Power P = VI = 5 × 0.2 = 1W = 1 J/s. Answer: (d) 1 J/s.
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Ans. The terminal voltage equation is V = ɛ – Ir, comparing with y = mx + c, the slope is -r and the intercept is ɛ. Thus, the correct answer is (a) -r and ɛ.
Let each cell have emf E and internal resistance r. For aiding: (12E + 2E) / R = 3A → 14E/R = 3. For opposing: (12E – 2E) / R = 2A → 10E/R = 2. Solving, x = 2 ...
For two parallel 1.5V cells, total external resistance is 10Ω. Using V = E – Ir and solving with V = 1.2V, we get r = 5Ω. Answer: (c) 5Ω.
The heat produced in a conductor is proportional to the square of the current (H ∝ I²). If the current is tripled, the heat increases by 3² = 9 times. Thus, the temperature rise will be 4°C × 9 = ...