QBManager

Current Electricity

152531 A battery is charged at a potential of $15 V$ in $8 h$ when the current flowing is $10 A$ . The battery on discharge supplies a current of $5 A$ for $15 h$ . The mean terminal voltage during discharge is $14 V$ . The watt- hour efficiency of battery is

1

80 %

2

90 %

3

87.5 %

4

82.5 %

Explanation:

C Electrical energy $=$ Voltage $\times$ Power $\times$ Time Input Energy $= 15 \times 10 \times 8 J$
Output Energy $= 14 \times 5 \times 15 J$
$%$ Watt - hour efficiency $= \frac{14 \times 5 \times 15}{15 \times 10 \times 8} \times 100$
$= \frac{7}{8} \times 100$
$= 87.5 %$

VITEEE-2014

Current Electricity

152554 A battery of emf $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered in it is maximum, is given by

1

0.5 Ω

2

1.0 Ω

3

2.0 Ω

4

0.25 Ω

Explanation:

A
Maximum power is delivered when internal resistance $=$ external resistance
$r = R$
$R = 0.5 Ω$

AIPMT-1992

Current Electricity

152564 A lead-acid battery of a car has an e.m.f. of 12 $V$ . If the internal resistance of the battery is 0.5 ohm, the maximum current that can be drawn from the battery will be

1

30 A

2

20 A

3

6 A

4

24 A

Explanation:

D Given that,
$E = 12 Volt$
$r = 0.5 ohm$
Then maximum current drawn from battery
$i = \frac{E}{r} = \frac{12}{0.5} = 24 A$

DCE-2009

Current Electricity

152588 Which of the following are true when the cells are connected in series?

1 Current capacity decreases

2 Current capacity increases

3 The emf decrease

4 The emf increases

Explanation:

D :
The negative terminal of cell is connected to $+ v e$ terminal of another cell and so on.
So, $E_{eff} = nE$
$R_{eff} = r + r + r + \dots \dots \dots . r = nr$
Hence, $E_{eff}$ is increases

CG PET- 2007

Current Electricity

152531 A battery is charged at a potential of $15 V$ in $8 h$ when the current flowing is $10 A$ . The battery on discharge supplies a current of $5 A$ for $15 h$ . The mean terminal voltage during discharge is $14 V$ . The watt- hour efficiency of battery is

1

80 %

2

90 %

3

87.5 %

4

82.5 %

Explanation:

C Electrical energy $=$ Voltage $\times$ Power $\times$ Time Input Energy $= 15 \times 10 \times 8 J$
Output Energy $= 14 \times 5 \times 15 J$
$%$ Watt - hour efficiency $= \frac{14 \times 5 \times 15}{15 \times 10 \times 8} \times 100$
$= \frac{7}{8} \times 100$
$= 87.5 %$

VITEEE-2014

Current Electricity

152554 A battery of emf $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered in it is maximum, is given by

1

0.5 Ω

2

1.0 Ω

3

2.0 Ω

4

0.25 Ω

Explanation:

A
Maximum power is delivered when internal resistance $=$ external resistance
$r = R$
$R = 0.5 Ω$

AIPMT-1992

Current Electricity

152564 A lead-acid battery of a car has an e.m.f. of 12 $V$ . If the internal resistance of the battery is 0.5 ohm, the maximum current that can be drawn from the battery will be

1

30 A

2

20 A

3

6 A

4

24 A

Explanation:

D Given that,
$E = 12 Volt$
$r = 0.5 ohm$
Then maximum current drawn from battery
$i = \frac{E}{r} = \frac{12}{0.5} = 24 A$

DCE-2009

Current Electricity

152588 Which of the following are true when the cells are connected in series?

1 Current capacity decreases

2 Current capacity increases

3 The emf decrease

4 The emf increases

Explanation:

D :
The negative terminal of cell is connected to $+ v e$ terminal of another cell and so on.
So, $E_{eff} = nE$
$R_{eff} = r + r + r + \dots \dots \dots . r = nr$
Hence, $E_{eff}$ is increases

CG PET- 2007

Current Electricity

152531 A battery is charged at a potential of $15 V$ in $8 h$ when the current flowing is $10 A$ . The battery on discharge supplies a current of $5 A$ for $15 h$ . The mean terminal voltage during discharge is $14 V$ . The watt- hour efficiency of battery is

1

80 %

2

90 %

3

87.5 %

4

82.5 %

Explanation:

C Electrical energy $=$ Voltage $\times$ Power $\times$ Time Input Energy $= 15 \times 10 \times 8 J$
Output Energy $= 14 \times 5 \times 15 J$
$%$ Watt - hour efficiency $= \frac{14 \times 5 \times 15}{15 \times 10 \times 8} \times 100$
$= \frac{7}{8} \times 100$
$= 87.5 %$

VITEEE-2014

Current Electricity

152554 A battery of emf $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered in it is maximum, is given by

1

0.5 Ω

2

1.0 Ω

3

2.0 Ω

4

0.25 Ω

Explanation:

A
Maximum power is delivered when internal resistance $=$ external resistance
$r = R$
$R = 0.5 Ω$

AIPMT-1992

Current Electricity

152564 A lead-acid battery of a car has an e.m.f. of 12 $V$ . If the internal resistance of the battery is 0.5 ohm, the maximum current that can be drawn from the battery will be

1

30 A

2

20 A

3

6 A

4

24 A

Explanation:

D Given that,
$E = 12 Volt$
$r = 0.5 ohm$
Then maximum current drawn from battery
$i = \frac{E}{r} = \frac{12}{0.5} = 24 A$

DCE-2009

Current Electricity

152588 Which of the following are true when the cells are connected in series?

1 Current capacity decreases

2 Current capacity increases

3 The emf decrease

4 The emf increases

Explanation:

D :
The negative terminal of cell is connected to $+ v e$ terminal of another cell and so on.
So, $E_{eff} = nE$
$R_{eff} = r + r + r + \dots \dots \dots . r = nr$
Hence, $E_{eff}$ is increases

CG PET- 2007

Current Electricity

152531 A battery is charged at a potential of $15 V$ in $8 h$ when the current flowing is $10 A$ . The battery on discharge supplies a current of $5 A$ for $15 h$ . The mean terminal voltage during discharge is $14 V$ . The watt- hour efficiency of battery is

1

80 %

2

90 %

3

87.5 %

4

82.5 %

Explanation:

C Electrical energy $=$ Voltage $\times$ Power $\times$ Time Input Energy $= 15 \times 10 \times 8 J$
Output Energy $= 14 \times 5 \times 15 J$
$%$ Watt - hour efficiency $= \frac{14 \times 5 \times 15}{15 \times 10 \times 8} \times 100$
$= \frac{7}{8} \times 100$
$= 87.5 %$

VITEEE-2014

Current Electricity

152554 A battery of emf $10 V$ and internal resistance $0.5 Ω$ is connected across a variable resistance $R$ . The value of $R$ for which the power delivered in it is maximum, is given by

1

0.5 Ω

2

1.0 Ω

3

2.0 Ω

4

0.25 Ω

Explanation:

A
Maximum power is delivered when internal resistance $=$ external resistance
$r = R$
$R = 0.5 Ω$

AIPMT-1992

Current Electricity

152564 A lead-acid battery of a car has an e.m.f. of 12 $V$ . If the internal resistance of the battery is 0.5 ohm, the maximum current that can be drawn from the battery will be

1

30 A

2

20 A

3

6 A

4

24 A

Explanation:

D Given that,
$E = 12 Volt$
$r = 0.5 ohm$
Then maximum current drawn from battery
$i = \frac{E}{r} = \frac{12}{0.5} = 24 A$

DCE-2009

Current Electricity

152588 Which of the following are true when the cells are connected in series?

1 Current capacity decreases

2 Current capacity increases

3 The emf decrease

4 The emf increases

Explanation:

D :
The negative terminal of cell is connected to $+ v e$ terminal of another cell and so on.
So, $E_{eff} = nE$
$R_{eff} = r + r + r + \dots \dots \dots . r = nr$
Hence, $E_{eff}$ is increases

CG PET- 2007