Passive Components MCQ Quiz in मल्याळम - Objective Question with Answer for Passive Components - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

From KCL we have:

I₁ + I₄ = I₂ + I₃

7 + 3 = 2 + I₃

I₃ = 8 A

Given that, inductance (L) = 5 H

Current (I) = 6 A

Energy stored in the inductor is,

• An inductor stores energy because of the magnetic field inside it. The energy stored by an inductor carrying a current I is given by:

          Energy = 

          L = Inductance of the coil

• An inductor does not allow a sudden change in current whereas a capacitor does not allow a sudden change in voltage across it.
• The inductive reactance for an inductor is X_L = ωL. For DC input, i.e. for ω = 0 rad/sec, the resistance/reactance offered by the inductor will be 0 Ω. So an inductor acts as a short circuit to DC.
• The combination of an indicator and capacitor called an LC filter, is used to reduce the ripple in the voltage.

From the circuit diagram,

⇒ 12 = 100 R_in + 10

⇒ R_in = 0.02 Ω

Concept:

The below equation shows the method to find the resistance:

Resistor Colour Coding uses colored bands to easily identify a resistor resistive value and its percentage tolerance. The resistor color code markings are always read one band at a time starting from the left to the right, with the larger width tolerance band oriented to the right side indicating its tolerance. 

The value of the resistance is given in the form:

R = AB × C ± D%

Where,

‘A’ and ‘B’ indicates the first two significant figures of resistance (Ohms).

‘C’ indicates the decimal multiplies.

‘D’ indicates the tolerance in percentage.

The table for the resistor color code is given below:

The gold color code indicates 5% tolerance.

Shortcut Trick

BB ROY Great Britain Very Good Watch Gold and Silver

B - Black (0)

B - Brown (1)

R - Red (2)

O - Orange (3)

Y - Yellow (4)

G - Green (5)

B - Blue (6)

V - Violet (7)

G - Grey (8)

W - White (9)

Tolerance - Gold(5%) and Silver(10%)

Concept:

Parallel Circuit: 

When resistors are connected with several conducting paths between the sources of emf. In a parallel connection, the voltage remains the same across all resistors, but the current will be different.

Total resistance  

Current in each resistor is different and can be calculated by using Ohm’s law

The total current is the sum of the three separate currents

When two resistors ‘R₁’ and ‘R2’ are in parallel connection then their equivalent resistance is given by

Series Circuit: 

When resistors are connected with only one conducting path they are said to be connected in series. The same current flows through all resistances but the voltage drop will be different and proportional to the resistance. 

The total resistance in a series circuit is given as

R_eq = R1 + R2 + R3

In a series connection, the resistances are connected end-to-end

When two resistors ‘R1’ and ‘R2’ are connected in series connection, then their equivalent resistance is given by

Req = R1 + R2

Calculation:

Given that 12 Ω and 24 Ω is connected in parallel

Equivalent resistance 

∴ Total Resistance between A and B

The resistance of a copper wire decreases when the diameter increases.

Explanation:

The resistance of copper is inversely proportional to the diameter of the wire hence when diameter decreases the resistance of a copper wire increases.

And also copper has a positive temperature coefficient of resistance i.e. as temperature increases resistance increases.

Effect of temperature on resistance of different material:

Conductor: When the temperature of conducting material increases, the resistance of that particular material increases.

Insulator: When the temperature of the material increases, the resistance of that particular material decreases.

Semiconductor: When the temperature of the material increases, the resistance of that particular material decreases.

Carbon is a non-metal, semiconductor and its resistance decreases with an increase in temperature.

Constantan is a Nickel-Copper based alloy wire that has a high resistivity and is mainly used for thermocouples and electrical resistance heating. It contains 60% of nickel and 40%, copper. It has a constant resistivity over a wide range of temperatures.

 which has a positive temperature coefficient which causes an increase in resistance due to an increase in temperature.

The capacitive reactance is given by:

f = Frequency of the voltage/current applied across the capacitor.

C = Capacitance value

For DC:

A DC signal is a zero frequency signal, i.e. f = 0 Hz

XC for f = 0 will be:

Note: A capacitor passes AC signals and blocks DC signals.

For AC:

AC signal is a signal having a particular frequency 'f',

XC for any frequency f is given by:

Observation:

• For DC we conclude that a capacitor provides infinite resistance to the flow of current. Hence no current will flow as current in a capacitive circuit is given by:

• For AC we observe that the resistance offered by the capacitor is finite. Hence a finite flow of current is possible in a capacitive circuit with AC input.

In the given circuit the four resistors are in parallel. When n resistors are in parallel total resistance

R = 1kΩ/4 = 250 Ω

According to the maximum power transfer theorem, to obtain maximum power from external power from a source with finite impedance, the impedance of the load must be equal to source impedance.

Derivation:

From the above circuit, the current flowing through the load, ‘I’ is given as

Power transferred to the load,

In the above equation, RL is a variable, therefore the condition for maximum power delivered to the load is determined by differentiating load power with respect to the load resistance and equating it to zero.

→ (RL + RTH)2 = 2RL (RTH + RL)

→ RL + RTH = 2RL

→ RL = RTH