Advertisements
Advertisements
Question
A bulb marked 12 V, 24 W operates on a 12 volt car battery for 20 minutes. Calculate:
(i) The current flowing through it, and
(ii) The energy liberated.
Advertisements
Solution
Given, Voltage = 12 V, power = 24 W, time = 20 mins. = 1200 s.
(i) Currrent, I = `"P"/"V" = 24/12` = 2 A
(ii) energy liberated, H = VIt = 12 x 2 x 1200 = 28,800 J
APPEARS IN
RELATED QUESTIONS
Calculate the effective resistance between the points A and B in the network shown below in Figure 8.45
Find the effective resistance in the following circuit diagrams (Fig.):
A current of 0.3 A is flowing through a branch of 6 Ω resistors in a junction as shown in fig. . Calculate the
(a) P.d. across the junction XY,
(b) Current flowing through 9Ω and 24Ω
( c) P.d. across 24 Ω resistor, and
( d) e.m.f. of the cell.
Complete the following table. The first answer has been given as an example
| Quantity | Unit |
|
(a) Electrical potential Volt ( b) Resistance ( c) Power ( d) Energy ( e) Resistivity |
Volt ........ .......... ............ .............. |
Fill in the blank :
1 mA = ............................. A.
Explain, why the potential difference across the terminals of a cell is more when the cell is not in use than it is when the cell is being used.
State expression for Cells connected in series.
State the condition when it is advantageous to connect cells in parallel.
The flow of electric charge per unit time is called potential difference.
