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

The Correct option is 3

Concept

Resistance of conductor = \(\frac{\rho \times L}{A} = \frac{\rho \times L}{\Pi \times R^{2}}\) 

L = length of conductor

R = radius of the conductor

A = cross-section area of conductor

\(\mathbf{\rho }\) = Resistivity of a material

The resistance of a conductor is proportional to \(\frac{L}{R^{2}}\)

Additional point

Series resistance

• Two or more resistance connected in series so that the same current flows through them is called as series resistance.
• ​

Parallel resistance

• When two or more resistance connected in the same node so that the same voltage appears across them.
• 

The correct answer is option 3): (Red-Red-Yellow-Gold)

Concept:

The resistor consists of four bands on it.

Based on the color of the bands, the value of resistance of a particular resistor can be determined

The value of the resistance is given in the form:

R = AB × C ± D%

Calculation:

220 KΩ resistor having a 5 percent tolerance

Red corresponds to 2

First two bands Red Red

The multiplier band corresponds to 10⁴ and will be  yellow in color 

The tolerance band corresponds to 5 percent and will be gold in color

Color coding of 220 KΩ resistors is Red-Red-Yellow-Gold

• Even on changing the values of linear resistors, the voltage remains constant in the case of the ideal voltage source. 
• Ohm’s law defines current is proportional to the voltage when the load (resistance) is constant. 
• If the values of all the resistors are doubled, then the current across the resistor will be half. 
• If values of all the resistors are halved, then-current flow in each resistor becomes two times. 
• The voltage is distributed according to the ratio of resistors.
• Since doubling all resistor values does not change the ratio of resistors, the voltage drop across them stays the same.

CONCEPT:

• Resistances are available in small as well as in large values.
• The resistors are generally painted by a specific colour and a specific code is assigned to them. This is called colour coding of the resistance.
• The resistance value, tolerance, and wattage rating are generally printed on the body of the resistor as numbers or letters.

EXPLANATION:

• From the above diagram, we can see that the last band tells about tolerance. 
• Therefore a resistor which has a gold-coloured ring signifies that the resistor has ±5% tolerance.

Concept:

The equivalent resistance of two resistances connected in parallel is given by:

\(R_{eq}=\frac{R_1R_2}{R_1+R_2}\)

R1 and R2 are two resistances connected in parallel.

Also, The equivalent resistance of two resistances connected in series is given by:

R_eq = R₁ + R₂

Calculation:

The parallel combination of two 200 Ω resistances will be:

\(R_{eq}=\frac{200\times200}{200+200}=100~Ω\)

Similarly, the parallel combination of two 100 Ω resistances will be:

\(R_{eq}=\frac{100\times100}{100+100}=50~Ω\)

The circuit is redrawn as:

The series combination of four resistances connected in series will be:

R_eq = 50Ω + 50Ω + 100Ω + 100Ω

R_eq = 300 Ω

The equivalent can be redrawn as:

The effective resistance of the given circuit between terminals A and B will be:

\(R_{AB}=\frac{300\times300}{300+300}=150~Ω\)

Calculation:

Now equivalent resistance of parallelly connected 20 Ω & R resistor is

\({R_{eq}} = \frac{{20 \times R}}{{20 + R}} = \frac{{20R}}{{20 + R}}\)

Now circuit diagram is modified as

Now equivalent resistance between ‘A’ & ‘B’ is

R_AB = R + 10 + R_eq + 10

Where,

R_AB = 50 Ω (given)

\(\therefore 50 = R + 10 + \frac{{20R}}{{20 + R}} + 10\)

(20 + R)(30 - R) = 20 R

600 + 10R – R² = 20R

∴ R² + 10R – 600 = 0

∴ R² + 30R – 20R – 600 = 0

R(R + 30) – 20(R + 30) = 0

∴ (R – 20) (R + 30) = 0

Hence R = 20, -30

∴ R = 20 Ω

∵ Resistance can’t be negative

The correct answer is option 1):(Resistance)

Concept:

• Ohm's law states that the voltage across a conductor is directly proportional to the current flowing through it, provided all physical conditions and temperatures remain constant.
• The current is inversly proportional to reistance
• V = IR
•  R, is Resistance and has units of ohms, with the symbol Ω.
• Ohm's applicable for the linear conductor

Concept:

In a series-parallel connection of resistor circuit

When 'n' identical resistors of having a resistance of R ohms are connected in parallel,

​\({R_{parellel}} = \frac{R}{n}\) ohms ----(1)

When 'n' identical resistors of having a resistance of R ohms are connected in series,

\({R_{series}} = n \times R\) ohms

Calculation:

Given:

n = 10, R = 10Ω

From equation (1);

\({R_{parellel}} = \frac{10}{10}=1\Omega\)

First two bands indicate digit, third band indicates multiplier and fourth band indicates tolerance.

We need 1.5 Ω.

R = 15 × 10^-1

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 \( \frac{1}{{{R}}}= \frac{1}{{{R_1}}} + \frac{1}{{{R_2}}} + \frac{1}{{{R_3}}}\) 

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

\({I_1} = \frac{V}{{{R_1}}},{I_2} = \frac{V}{{{R_2}}},{I_3} = \frac{V}{{{R_3}}}\)

The total current is the sum of the three separate currents

\(I = {I_1} + {I_2} + {I_3}\)

Series Circuit: When resistors are connected with only one conducting path they are said to be connected in series. The same current flows through the 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 = R1 + R2 + R3

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