How much energy is dissipated as heat in 20 s by a 100 Ω resistor that carries a current of 0.5 A?
Correct answer: D. 500 J
- A. 50 J
- B. 100 J
- C. 250 J
- D. 500 J
Explanation
To determine the energy dissipated as heat in a resistor, use the formula: H = I² Rt. For this question, I = 0.5 A, R 100 Ω, and t = 20s. Applying these values:H = (0.5)2 x 100 x 20 = 500 J, confirming that Option D is correct. Other options result from either incorrect squaring of the current or misapplication of the formula, or arithmetic errors.
Last updated
About Current Electricity
Steady current relates charge flow to potential difference, resistance and resistivity, including how temperature changes a conductor's resistance. Sources with internal resistance have terminal voltage below their emf when delivering current, and maximum power output occurs under a specific load condition rather than at zero resistance.
Practise Current Electricity
1,052 free Current Electricity MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
0.75 A current flows through an iron wire when a battery of 1.5 volts is connected across its ends. The length of the wire 5.0 m and its cross-sectional area is 2.5 x 10^-7 m2. What is the resistivity of iron?
1.6 mA current is flowing in conducting wire then the number of electrons flowing per second
1 kilo ohm = _ ohm
1 microvolt is
1/Req = 1/Rl + 1/R2 + 1/R3 + ..... +1/Rn is the combination in