Balbharati solutions for Physics [English] 11 Standard Maharashtra State Board chapter 11 - Electric Current Through Conductors [Latest edition]

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You are given four bulbs of 25 W, 40 W, 60 W, and 100 W of power, all operating at 230 V. Which of them has the lowest resistance?

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Which of the following is an ohmic conductor?

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A rheostat is used

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The wire of length L and resistance R is stretched so that its radius of cross-section is halved. What is its new resistance?

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Masses of three pieces of wires made of the same metal are in the ratio 1:3:5 and their lengths are in the ratio 5:3:1. The ratios of their resistances are

The internal resistance of a cell of emf 2 V is 0.1 Ω it is connected to a resistance of 0.9 Ω. The voltage across the cell will be ______.

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100 cells each of emf 5V and internal resistance 1Ω are to be arranged so as to produce maximum current in a 25Ω resistance. Each row contains equal number of cells. The number of rows should be

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Five dry cells each of voltage 1.5 V are connected as shown in the diagram

What is the overall voltage with this arrangement?

Give reason/short answer.

In the given circuit diagram two resistors are connected to a 5V supply.

Calculate potential difference across the 8Ω resistor.

Give reason/short answer.

In the given circuit diagram two resistors are connected to a 5V supply.

A third resistor is now connected in parallel with 6Ω resistor. Will the potential difference across the 8Ω resistor the larger, smaller, or the same as before? Explain the reason for your answer.

Give reasons/short answer.

Prove that the current density of a metallic conductor is directly proportional to the drift speed of electrons.

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Distinguish between Ohmic and non-ohmic substances; explain with the help of example.

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DC current flows in a metal piece of the non-uniform cross-section. Which of these quantities remains constant along the conductor: current, current density, or drift speed?

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What is the resistance of one of the rails of a railway track 20 km long at 20° C? The cross-section area of the rail is 25 cm² and the rail is made of steel having resistivity at 20° C as 6 × 10^-8 Ω m.

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A battery after a long use has an emf 24 V and an internal resistance 380 Ω. Calculate the maximum current drawn from the battery? Can this battery drive starting motor of car?

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A battery of emf 12 V and internal resistance 3 Ω is connected to a resistor. If the current in the circuit is 0.5 A,

1. Calculate resistance of resistor.
2. Calculate terminal voltage of the battery when the circuit is closed.

The magnitude of current density in a copper wire is 500 A/cm². If the number of free electrons per cm³ of copper is 8.47 × 10²² calculate the drift velocity of the electrons through the copper wire (charge on an e = 1.6 × 10^-19 C)

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Three resistors 10 Ω, 20 Ω, and 30 Ω are connected in series combinations.

1. Find the equivalent resistance of series combination.
2. When this series combination is connected to 12V supply, by neglecting the value of internal resistance, obtain potential difference across each resistor.

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Two resistors 1 kΩ and 2 kΩ are connected in parallel combination.

1. Find equivalent resistance of parallel combination
2. When this parallel combination is connected to 9 V supply, by neglecting internal resistance calculate current through each resistor.

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A silver wire has a resistance of 4.2 Ω at 27° C and resistance 5.4 Ω at 100° C. Determine the temperature coefficient of resistance.

A 6 m long wire has diameter 0.5 mm. Its resistance is 50 Ω. Find the resistivity and conductivity.

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Find the value of resistance for the following colour code.

Blue Green Red Gold

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Find the value of resistance for the following colour code.

Brown Black Red Silver

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Find the value of resistance for the following colour code.

Red Red Orange Gold

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Find the value of resistance for the following colour code.

Orange White Red Gold

Find the value of resistance for the following colour code.

Yellow Violet Brown Silver

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Find the colour code for the following value of resistor having tolerance ± 10%

330 Ω

Solve the following problem.

Find the colour code for the following value of resistor having tolerance ± 10%

100 Ω

Solve the following problem.

Find the colour code for the following value of resistor having tolerance ± 10%

47 kΩ

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Find the colour code for the following value of resistor having tolerance ± 10%

160 Ω

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Find the colour code for the following value of resistor having tolerance ± 10%

1 KΩ

Solve the following problem.

A current 4A flows through an automobile headlight. How many electrons flow through the headlight in a time 2hrs?

Solve the following problem.

The heating element connected to 230V draws a current of 5A. Determine the amount of heat dissipated in 1 hour (J = 4.2 J/cal.).