Current Electricity - Emf of cell, Internal resistance

A Carbon Resistor is marked in colour bands of Red, Black,Orange,Silver.What is the resistance and tolerance value of the resistor ?

• 20 kilo ohm & +- 10%

• 18 kilo ohm & +-5%

• 25 kilo ohm & +- 10%

• 20 kilo ohm

A cell of emf (E) and internal resistance (r) draws a current (I). Write a relation between terminal voltage (V) in terms of E,I,r. ?

As the temperature of a conductor increases both it's Resistivity and Conductivity change.Will the ratio of its Resistivity and conductivity

• Increases

• Decreases

• Remain same

• None of these

What will be the new resistivity of a metallic wire if it's length becomes double

• Increases two times

• Becomes half

• Increases four times

• Remains same

15. From the graph between current I and voltage V shown below, identify the portion corresponding to negative resistance

• (a) AB

• (b) BC

• (c) CD

• (d) DE

16. Which of the following I-V graph represents ohmic conductors?

• (a) A

• (b) B

• (c) C

• (d) D

20. The resistivity of alloy manganin is

• (a) Nearly independent of temperature

• (b) Increases rapidly with increase in temperature

• (c) Decreases with increase in temperature

• (d) Increases rapidly with decrease in temperature

A car battery has an emf of 12V and an internal resistance of 0.005Ω. The terminal voltage when a load current of 100A is drawn is...

• 11.5V

• 0.5V

• 7.0V

• 11.5A

The cell has internal resistance, r, and electromotive force of 1.5 V.
What is the reading of voltmeter when the switch is closed?

• More than 3.0 V
• Less than 1.5 V
• More than 1.5 V
• 1.5 V

A battery has an e.m.f of 6.0 V. When it is connected to an external resistor, the potential different is 2.6 V and the current is 0.6 A. 
What is the value of the internal resistance?

• 3.4 Ω
• 4.3 Ω
• 4.4 Ω
• 5.7 Ω