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प्रश्न
Define the following:
One ohm
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उत्तर
One ohm is the resistance of a component when the potential difference of one volt applied across the component drives a current of one ampere through it.
संबंधित प्रश्न
Find the resistance of a conductor if 0.24 A current is passing through it and a potential difference of 24 V is applied across it.
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.
A low voltage supply from which one needs high currents must have very low internal resistance. Why?
Name the unit of electrical resistance and give its symbol.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Calculate the value of the resistance of the resistor.
Name the law which is illustrated by the above V−I graph.
A car bulb connected to a 12 volt battery draws 2 A current when glowing. What is the resistance of the filament of the bulb? Will the resistance be more same or less when the bulb is not glowing?
Show by a diagram how two resistors R1 and R2 are joined in parallel. Obtain an expression for the total resistance of the combination.
How does an increase in the temperature affect the specific resistance of a :
(i) Metal and
(ii) Semiconductor ?
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.
Tick(✓) the correct choice in the following:
Ohm's law is applicable to
- Name and state the law which relates the potential difference and current in a conductor.
- What is the necessary condition for a conductor to obey the law named above in part (a) ?
State Ohm’s law.
The temperature of a conductor is increased. The graph best showing the variation of its resistance is:
State Ohm’s law? How can it be verified experimentally? Does it hold good under all conditions? Comment.
A metal rod of length 10 cm and a rectangular cross-section of 1 cm × `1/2` cm is connected to a battery across opposite faces. The resistance will be ______.
Two conductors are made of the same material and have the same length. Conductor A is a solid wire of diameter 1 mm. Conductor B is a hollow tube of outer diameter 2 mm and inner diameter 1 mm. Find the ratio of resistance RA to RB.
Vinita and Ahmed demonstrated a circuit that operates the two headlights and the two sidelights of a car, in their school exhibition. Based on their demonstrated circuit, answer the following questions.
- State what happens when switch A is connected to:
a) Position 2
b) Position 3 - Find the potential difference across each lamp when lit.
- Calculate the current.
a) in each 12 Ω lamp when lit.
b) In each 4 Ω lamp when lit.
OR - Show, with calculations, which type of lamp, 4.0 Ω or 12 Ω, has the higher power.
