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
The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below:
| I (amperes) | 0.5 | 1.0 | 2.0 | 3.0 | 4.0 |
| V (volts) | 1.6 | 3.4 | 6.7 | 10.2 | 13.2 |
Plot a graph between V and I and calculate the resistance of that resistor.
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?
Keeping the potential difference constant, the resistance of a circuit is doubled. By how much does the current change?
If the potential difference between the end of a wire of fixed resistance is doubled, by how much does the electric power increase?
How is the electric potential difference between the two points defined? State its S.I. unit.
Define the following:
Potential difference
What is the combined resistance of each of the networks between A and B shown in fig. ?
What do you understand by the resistance of a wire?
From the following observations taken while determining the resistance of a conductor, draw the current-voltage graph and calculate the resistance of conductor. Is the conductor ohmic?
| Ammeter reading I (in ampere) | Voltmeter reading V (in volt) |
| 0.2 | 0.4 |
| 0.3 | 0.6 |
| 0.5 | 1.0 |
| 0.8 | 1.6 |
| 1.5 | 3.0 |
Find out the following in the electric circuit given in Figure
- Effective resistance of two 8 Ω resistors in the combination
- Current flowing through 4 Ω resistor
- Potential difference across 4 Ω resistance
- Power dissipated in 4 Ω resistor
- Difference in ammeter readings, if any.
