MEDIUM
12th CBSE
IMPORTANT
Earn 100

A cell of unknown emf ε and internal resistance r, two unknown resistances R1 and R2R2>R1 and a perfect ammeter are given. The current in the circuit is measured in five different situations:

Without any external resistance in the circuit

The current obtained in the five cases are :

0.42 A, 0.6 A, 1.05 A, 1.4 A, and 4.2 A

but not necessarily in that order. Identify the currents in the five cases listed above and calculate E, r, R1 and R2.

Important Questions on Current Electricity

MEDIUM
12th CBSE
IMPORTANT

A cell of unknown emf ε and internal resistance r, two unknown resistances R1 and R2R2>R1 and a perfect ammeter are given. The current in the circuit is measured in five different situations:

With resistance R1 only

MEDIUM
12th CBSE
IMPORTANT

A cell of unknown emf ε and internal resistance r, two unknown resistances R1 and R2R2>R1 and a perfect ammeter are given. The current in the circuit is measured in five different situations:

With resistance R2 only

EASY
12th CBSE
IMPORTANT

A cell of unknown emf ε and internal resistance r, two unknown resistances R1 and R2R2>R1 and a perfect ammeter are given. The current in the circuit is measured in five different situations:

With both R1 and R2 used in series combination, and

The current obtained in the five cases are :

0.42 A, 0.6 A, 1.05 A, 1.4 A, and 4.2 A

but not necessarily in that order. Identify the currents in the five cases listed above and calculate E, r, R1 and R2.

MEDIUM
12th CBSE
IMPORTANT

A cell of unknown emf ε and internal resistance r, two unknown resistances R1 and R2R2>R1 and a perfect ammeter are given. The current in the circuit is measured in five different situations:

With R1 and R2 used in parallel combination.

The current obtained in the five cases are :

0.42 A, 0.6 A, 1.05 A, 1.4 A, and 4.2 A

but not necessarily in that order. Identify the currents in the five cases listed above and calculate E, r, R1 and R2.

MEDIUM
12th CBSE
IMPORTANT
A battery consists of 12 cells in series, each having an emf E and internal resistor r. Some of the cells in the battery are connected with wrong polarity. This battery is connected to another source of emf 2E and internal resistance 2r. An ammeter in the circuit reads 3A when battery and the source aid each other and 2A in the same direction when they oppose each other. Find how many cells in the battery are connected with wrong polarity.
MEDIUM
12th CBSE
IMPORTANT

In the circuit shown in Fig. , each battery is of 5 V and has an internal resistance of 0.2Ω. What will be the reading of an ideal voltmeter connected across a battery?

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MEDIUM
12th CBSE
IMPORTANT
Determine the percentage by which the illumination of a lamp will decrease if the current drops by 20%.
MEDIUM
12th CBSE
IMPORTANT

In the circuit shown in Fig. , the heat produced in 5Ω resistor, due to the current flowing through it is 10 calorie per second. Find the heat produced in 4Ω resistor.

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