Advertisements
Advertisements
प्रश्न
Fill in the following blank with suitable words:
Resistance is measured in .............. The resistance of a wire increases as the length ..............; as the temperature ..............; and as the cross-sectional area .............. .
Advertisements
उत्तर
Resistance is measured in ohm (Ω). The resistance of a wire increases as the length increases; as the temperature increases; and as the cross-sectional area decreases.
APPEARS IN
संबंधित प्रश्न
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
What is Resistivity?
Name the law which is illustrated by the above V−I graph.
The graph between V and I for a conductor is a straight line passing through the origin.
What should remain constant in a statement of this law?
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.
How would you connect two resistors in series? Draw a diagram. Calculate the total equivalent 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.
In the circuit shown below in Fig, calculate the value of x if the equivalent resistance between A and B is 4 Ω.
Calculate the electric field in a copper wire of cross-sectional area 2.0 mm2 carrying a current of 1 A.
The resistivity of copper = 1.7 × 10–8 Ω m
Fig. represents the circuit used for the verification of ohm's law. Label the different parts from A and F. State the function of each.
What is meant by the drift speed of free electrons?
What are non-ohmic conductors? Give one exmaple. Draw a current-voltage graph for a non-ohmic conductor.
State microscopic form of Ohm’s law.
Explain the equivalent resistance of a series resistor network.
Two cells each of 5V are connected in series across an 8Ω resistor and three parallel resistors of 4Ω, 6Ω, and 12Ω. Draw a circuit diagram for the above arrangement. Calculate
- the current drawn from the cell
- current through each resistor
A current of 2amp flowing through a conductor produced 80 joule of heat in 10 sec. The resistance of the conductor is:-
Two cells of same emf E but internal resistance r1 and r2 are connected in series to an external resistor R (Figure). What should be the value of R so that the potential difference across the terminals of the first cell becomes zero.
How is electric current related to the potential difference across the terminals of a conductor?
Draw a labelled circuit diagram to verify this relationship.
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.
