Answer a) The amount of work done when an electric charge Q moves against a potential difference V is: W = Q V = W = Q V = W = Q V = W = Q V (1) We all know that current I = Q/T. IT = Q (2)...
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
Answer Because of their low resistance, the connecting wires leading to the heater are somewhat warmer than the wires that heat the heater element. This results in a flow of minimal heat generation...
Why is an electric bulb not filled with air? Explain why argon or nitrogen is filled in an electric bulb.
Answer Because an electric bulb's filament is comprised of tungsten, which would quickly burn if it came into touch with oxygen in the air, it is not filled with air. Unreactive gases like argon and...
Q10. a) Write down the formula for the heat produced when a current I is passed through a resistor R for time t. b) An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.
Answer a) The following is the formula for calculating the amount of heat produced: I2Rt = H b) Assumed R equals 20 5 amps = I t = 30 seconds We are aware of this. I2Rt = H We know H = 15000J by...
What is the maximum resistance which can be made using five resistors each of 1/5 Ω?
(a) 1/5 Ω
(b) 10 Ω
(c) 5 Ω
(d) 1 Ω
Solution: The answer is (d) 1 Ω Resistance is maximized by connecting resistors in series.$$\begin{aligned}& R =\frac{1}{5}+\frac{1}{5}+\frac{1}{5}+\frac{1}{5}+\frac{1}{5} \&=5 / 5 \&=1...