# Electrical Resistivity and Electrical Conductivity

## Trending Questions

**Q.**

Unit of electric power may also be expressed as

Volt ampere

Kilowatt hour

Watt second

Joule second

**Q.**

What determines the rate at which energy is delivered by a current?

**Q.**

An Electric Bulb Of Resistance $200\Omega $ Draws A Current Of $1$ Ampere. Calculate The Power Of The Bulb The Potential Difference At Its Ends And The Energy In Kwh Consumed Burning It For $5\mathrm{H}$.

**Q.**How much energy is transferred when 10 A current flows through a resistor of resistance 5 Ω for time of 30 minutes?

0.25 kWh

3.2 kWh

0.025 kWh

1.2 kWh

**Q.**When length of a wire and area of cross-section both are doubled, then its resistance will ______.

- reduce to half
- increase twice
- remain same
- increase four times

**Q.**

Question 12

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be

(a) 100%

(b) 200%

(c) 300%

(d) 400%

**Q.**

What is electric power?

**Q.**Question 12

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be

(a) 100%

(b) 200%

(c) 300%

(d) 400%

**Q.**

A wire of resistance 2 Ω is stretched to double its length such that its volume remains constant. What is the resistance of the stretched wire?

2 Ω

8 Ω

6 Ω

10 Ω

**Q.**Masses of three wires of copper are in the ratio 1 : 3 : 5 and their lengths are in the ratio of 5 : 3 : 1. The ratio of their electrical resistances are

- 1:3:5
- 5:3:1
- 1:15:125
- 125:15:1

**Q.**

What is the resistance of a circuit with voltage 40 V and current 8 A?

- 5 ohm
32 ohm

10 ohm

- 32 ohm

**Q.**

If a metallic wire of resistance R is melted and recast to half of its length, the new resistance of the wire will be?

R4

R2

2R

R

**Q.**Match the resistances that an ideal conductor offers at different temperatures.

- Zero resistance
- Low resistance
- High resistance

**Q.**Find the resistance of a hollow cylindrical pipe of length 1 m whose inner and outer radii are 10 cm and 20 cm respectively. Assume that the cylindrical pipe is made of a material of resistivity 2×10−8 Ω m.

0.21 m Ω

0.21 Ω

0.21 μ Ω

21 Ω

**Q.**Circuit 1 and circuit 2 consists of resistor R1 and R2 respectively. These resistors have same resistivity and thickness. Length of R1 > length of R2. If same voltage is applied across the circuits, which circuit has more current?

- Circuit 1
- Equal currents
- Insufficient information
- Circuit 2

**Q.**Find the ratio of the maximum to the minimum resistance for a combination of 'n' equal resistors.

- n2
- 1n
- n
- 1n2

**Q.**If 150 J s−1 is required for an appliance to run, what is the power consumed by it, if it is operated at 240 V?

- 24 W
- 150 W
- 15 W
- 360 W

**Q.**

A bulb is joined to a battery of emf 4 V and internal resistance of 2.5 Ω.A steady current of 0.5 A flows through circuit. calculate-

(a) Total energy provided by battery in 10 minutes

**Q.**The factor(s) affecting the resistance of a conductor is/are:

- Length of the conductor
- Area of cross-section of the conductor
- Material of the conductor
- Color of the conductor