Question

100J of work is done in transferring 20c of charge between two points in a conductor find the resistance offered by the conductor if a current of 2A flows through it

Answer 1

Explanation:

The work done when a unit charge is carried from “one point to another” is the potential difference.  

$V=\frac{1 J}{1 C}$

$\mathrm{V}=\frac{100}{20}$

= 5 volts

Resistance is the property of any material to allow an electric current to pass through it or the opposing force of the material to electric flow.

The unit of resistance is ohms.  

The formula for calculating resistance: $R=\frac{v}{I}$

where R is the ‘resistance’,  

V is the ‘potential difference’,  

I is the ‘current flowing’.

V= 5 volts

I = 2A

$\mathrm{R}=\frac{5}{2}$

= 2.5 ohms

Resistance = 2.5 ohms .

Answer 2

Answer:

The resistance offered is 2.5 ohms.

Given data:

Work done: 100 J

Charge Q = 20 C

Current I = 2 A.

Finding potential difference V from the relation of work done on a particular charge.

V=W/Q

So,

V= $\frac{100 \mathrm{J}}{20 \mathrm{C}}$

V=  5 Volts

The potential in the circuit is 5 Volts.

According to Ohms law, the potential in a circuit (in volts) is equal to the product of current and resistance in the circuit.

V=  IR

Resistance R= $\frac{V}{I}=\frac{5}{2}$

R=2.5 ohm.  

Therefore the resistance needed for the circuit to have potential of 5 volts is 2.5 ohm.