Question

When resisrance of a 1m long nicrome wire is 6 if we reduce the length of wire tob70cm what will be its resistance?

Answer 1

Crack Challenges

→ R = p × l/A

• R = Resistance
• p = Resistivity
• l = Length
• A = Cross Section Area

→ 6 = p × 1/A

According to question

→ R = p × (70/100)m/A

→ R = p × 70/100A

→ R = 70/100 (p × 1/A)

→ R/6 = 70/100(p × 1/A)/(p × 1/A)

→ R/6 = 70/100

→ R = 70/100 × 6

→ R = 420/100 = 4.2 Ω

New resistance is 4.2 Ω.

Answer 2

Answer:

4.2 is the new resistance.

Explanation:

1. Resistance of a 1m long nicrome wire is 6 if we reduce the length of wire to 70cm.
2. To find what will be its new resistance.
3. Let us assume this formula:
4. Resistance = Resisvity × Length / Cross Area.
5. In short form { R = P × L / A }

Using form → R= P × 1 / A

= 6 = P × 1 / A

= R = P × ( 70 / 100 ) m / A

= R = 70 / 100 ( P × 1 / A )

= R / 6 = 70 / 100 ( P × 1 / A ) (P × 1 / A )

= R / 6 = 70 / 100

= 70 / 100 × 6

= R = 420 / 100 = 4.2

Therefore , 4.2 is the new resistance.