Ohmic and Non Ohmic Resistors

Q. Derivation of the electric field at any point due to a electric dipole.

Q.

Explain how a potential barrier is developed in a p-n junction diode.

Q. Define resistance of a conductor. Give its SI unit.
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Q.

Give two differences between an ohmic and non-ohmic resistor.

Q.

Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the same source? Why?

Q. what do you mean by ohmic and non ohmic resistors ?

Q.

What is an ohmic resistor ? Give one example of an ohmic resistor. Draw a graph to show its current-voltage relationship. How is the resistance of the resistor determined from this graph?

Q.

The potential difference between A and B in the following situation is:

Q.

V=IR, from this equation it's clear that V is directly proportional to I and R..
I=V/R, from this equation it's clear that I is directly proportional to V and inversely proportional to R.
But when V is directly proportional to R and I is directly proportional to V then why is I not directly proportional to R?

Q. Why does the current always remain the same in a series circuit? When the charges encounter a resistor, wouldn't the speed of flow decrease? If the speed decreases, shouldn't the rate of flow decrease at the same time?

Q.

The Ohm's law states that at constant temperature the current flowing through a conductor is directly proportional to the potential difference across its ends . This means that I proportional to V. Two equate this we need to add a constant. This we get V=R*I . But why can't we write the same equation by adding a constant on the other side as I=R*V . How do we know which side to add the constant and how?

Q.

What are non-ohmic resistors ? Give one example and draw a graph to show its current voltage relationship.

Q. The given figure shows three resistors of $2\Omega$, $4\Omega$ and $R\Omega$ connected to a battery of EMF 2V and internal resistance $3\Omega$.A main current of 0.25 A flows through the circuit.

(a) What is the potential difference across the $4\Omega$ resistor?
(b) Calculate the potential difference across the internal resistance of the cell.
(c) What is the potential difference across the $R\Omega$ or $2\Omega$ resistors?
(d) Calculate the value of R.
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Q. Is there any Difference between rheostat and Jockey.

Q. Why ammeter burns out when connected in parallel?

Q.

Rheostat -> Changes current without changing voltage

But if current inverses, voltage should also because V proportional to I. Then how does rheostat do it?

Q. What would happen if voltmeter and ammeter position sre interchange in an electric circuit

Q.

Which of the following is an ohmic resistance?
(a) LED (b) junction diode (c) Filament of a bulb (d) nichrome wire

Q. A cell supplies a current of 0.6 A through a $2\Omega$ coil and a current of 0.3 A through and $8\Omega$ coil. Calculate the EMF and the internal resistance of the cell.
[4 MARKS]

Q.

The graph of potential difference (V) versus current (I) for an ohmic resistor is a straight line as shown below:

The resistance of the resistor can be determined from this graph as:

1. 

2. 

3. 

4. 

Q. What happens, if the household electric appliances are connected in series?

Q. The given figure shows two V-I graphs. Which of these represents ohmic conductor and which one represents non-ohmic conductor. Give the reason for your answer.

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Q.

According to Ohm's Law, what would be the resistance of a circuit with 40 volts and 8 amps?

Q.

What is the condition essential for a conductor to obey Ohms law?

Q.

The current-voltage relation of the diode is given by $I=(e^{1000V/T}–1)mA$, where the applied $V$ is in volts and the temperature $T$ is in degree Kelvin. If a student makes an error measuring ±$0.01V$ while measuring the current of $5mAat300K$, what will be the error in the value of current in $mA$

1. $0.2mA$

2. $0.02mA$

3. $0.5mA$

4. $0.05mA$

Q.

Fig 8.13 below shows the I-V characteristic curves for four resistors. Identify the ohmic and non-ohmic resistors. Give a reason for your answer.

Q.

What would be the effect on the current if the resistance is increased while the voltage remained constant?

1. Current would decrease.

2. Current would increase exponentially.

3. Current would increase.

4. Current would remain constant

Q. The V-I curve of the ohmic component is:

1. Linear
2. Parabolic
3. None of the above
4. Non-linear

Q. The resistance of a discharge tube is

1. Ohmic
2. Non-ohmic
3. Both (a) and (b)
4. Zero

Q.

Which of the following is an ohmic resistor?

1. LED

2. Filament of a bulb

3. Nichrome wire

4. Junction diode