Advertisements
Advertisements
प्रश्न
How much energy is consumed when a current of 5 amperes flows through the filament (or element) of a heater having resistance of 100 ohms for two hours? Express it in joules.
Advertisements
उत्तर
Given:
I = 5 A
R = 100 Î
Power consumed, P= I2R
= (5)2 100 watt
= 2500 watts=2.5 kW
Energy consumed, E = P x time
= 2.5 x 2
= 5 kWh
APPEARS IN
संबंधित प्रश्न
What will be the change in the current if the potential difference is kept constant and the resistance of the circuit is made four times?
- It will remain unchanged.
- It will become four times.
- It will become one-fourth.
- It will become half.
Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal?
Is Ohm’s law universally applicable for all conducting elements? If not, give examples of elements which do not obey Ohm’s law.
Find the expression for the resistivity of a material and state the SI unit of resistivity.
State Ohm’s law and draw a neat labelled circuit diagram containing a battery, a key, a voltmeter, an ammeter, a rheostat and an unknown resistance to verify it.
A wire of resistance 3 ohm and length 10 cm is stretched to length 30 cm. Assuming that it has a uniform cross section, what will be its new resistance?
Show by a diagram how two resistors R1 and R2 are joined in parallel. Obtain an expression for the total resistance of the combination.
A wire has a length of 2.0 m and a resistance of 5.0 Ω. Find the electric field existing inside the wire if it carries a current of 10 A.
Rewrite the following statement by selecting the correct option.
The S.I. unit of resistance is __________.
What are ohmic conductors? Give one exmaple. Draw a graph showing the current-voltage relationship for an ohmic conductor.
Draw a neat diagram for the verification of Ohm’s law by voltmeter-ammeter method. By another diagram show the relation between p.d. and current.
Choose the correct alternative.
Which of the following is an ohmic conductor?
SI unit of resistance is:
Ohm’s law states the relationship between power and voltage.
What is ohmic device?
An electronics hobbyist is building a radio which requires 150 Ω in her circuit, but she has only 220 Ω, 79 Ω, and 92 Ω resistors available. How can she connect the available resistors to get the desired value of resistance?
Let the resistance of an electrical device remain constant, while the potential difference across its two ends decreases to one fourth of its initial value. What change will occur in the current through it? State the law which helps us in solving the above stated question.
The voltage - current readings of a certain material are shown in the table given below:
| Voltage (V) | 10 V | 20 V | 30 V |
| Current (I) | 2 A | 3 A | 4 A |
Study the table.
- State whether the conductor used is ohmic or non-ohmic.
- Justify your answer.
- State Ohm's law.
Ohm's Law states that for a metallic conductor, the current flowing through it is directly proportional to the potential difference across its ends, provided that:
