Advertisements
Advertisements
प्रश्न
Choose the correct alternative.
Which of the following is an ohmic conductor?
विकल्प
transistor
vacuum tube
electrolyte
nichrome wire
Advertisements
उत्तर
nichrome wire
APPEARS IN
संबंधित प्रश्न
Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?
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.
The relationship between the potential difference and the current in a conductor is stated in the form of a law.
1) Name the law.
2) What does the slope of V-I graph for a conductor represent?
3) Name the material used for making the connecting wire.
What is an Ohmic resistor?
Write the formula of resistivity
Name the physical quantity whose unit is "ohm".
The resistors R1, R2, R3 and R4 in the figure given below are all equal in value.
What would you expect the voltmeter A, B and C to read assuming that the connecting wires in the circuit have negligible resistance?
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.
A resistance of 40 ohms and one of 60 ohms are arranged in series across 220 volt supply. Find the heat in joules produced by this combination of resistances in half a minute.
In an experiment of verification of Ohm’s law following observations are obtained.
|
Potential difference V (in volt) |
0.5 | 1.0 | 1.5 | 2.0 | 2.5 |
| current I (in ampere) | 0.2 | 0.4 | 0.6 | 0.8 | 1.0 |
Draw a V-I graph and use this graph to find:
- the potential difference V when the current I is 0.5 A,
- the current I when the potential difference V is 0.75 V,
- the resistance in a circuit.
In the circuit shown below in Fig, calculate the value of x if the equivalent resistance between A and B is 4 Ω.
Two metallic spheres A and B kept on insulating stands are in contact with each other. A positively charged rod P is brought near the sphere A as shown in the figure. The two spheres are separated from each other, and the rod P is removed. What will be the nature of charges on spheres A and B?
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.
Rewrite the following statement by selecting the correct option.
The S.I. unit of resistance is __________.
State and define Ohm’s law.
State the limitations of Ohm’s law.
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.
An ammeter placed in series with an electric radiator reads 0.5 amps and a voltmeter placed across it reads 230 volts. What is the resistance of the radiator?
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
Assertion: The statement of Ohm’s law is K = IR.
Reason: V = IR is the equation which defines resistance.
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.
What is the resistance of a conductor through which a current of 0.5 A flows when a potential difference of 2V is applied across its ends?
What is meant by resistance of a conductor ? Define its SI unit.
How is electric current related to the potential difference across the terminals of a conductor?
Draw a labelled circuit diagram to verify this relationship.
Why should an ammeter have low resistance?
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.
The circuit depicted in the figure is employed for studying Ohm’s Law. Instead of using a standard resistor, a student opts for a glass tube filled with mercury (tube 1), connected to the circuit through two electrodes, E1 and E2. He records the readings of the ammeter and voltmeter, thereby calculating the resistance. The student repeats the experiment by substituting tube 1 with tube 2, where the same amount of mercury fills tube 2.
Neglecting internal resistance of the cell use (> or < or =) to compare:
- the resistance in both the cases.
- the voltmeter readings in both the cases.
- the specific resistance in both the cases.
