Advertisements
Advertisements
Question
A current of 0.2 A flows through a wire whose ends are at a potential difference of 15 V. Calculate:
(i) The resistance of the wire, and
(ii) The heat energy produced in 1 minute.
Advertisements
Solution
Given, current, I= 0.2 A; p.d. = 15 V
(i) A/C to Ohm's law
V=IR
R = `"v"/"I" = 15/0.2 = 75 Omega`
(ii) energy produced in one minutes is:
H=I2 Rt = (0.2)2 x 75 x 60 =180 J
APPEARS IN
RELATED QUESTIONS
Define one coulomb charge.
Calculate the work done in moving a charge of 4 coulombs from a point at 220 volts to another point at 230 volts.
What is the potential difference between the terminals of a battery if 250 joules of work is required to transfer 20 coulombs of charge from one terminal of battery to the other?
The p.d. across a lamp is 12 V. How many joules of electrical energy are changed into heat and light when:
a charge of 1 C passes through it?
A resistance of 20 ohms has a current of 2 amperes flowing in it. What potential difference is there between its ends?
Explain the statement ‘the potential difference between two points is 1 volt’.
The V-I graph for a series combination and for a parallel combination of two resistors is shown in Fig – 8.38. Which of the two, A or B, represents the parallel combination? Give a reason for your answer.
Draw a graph of Potential difference (V) versus Current (I) for an ohmic resistor. How can you find the resistance of the resistor from this graph?
If P and V are the power and potential of device, the power consumed with a supply potential V1 is:
The SI unit of potential difference is ______.
