Answer / rajeshsan

Brushes with metal will lead arc and more wear & tear, Hence for large rating we will use carbon brushes. And for toy motor and very small motor use metal brushes.

Answer / mohanavel.u ,marg ltd

The carbon brushes are having the self lubricating capacity
and if metal is used it will lead to more wear and tear
produces spark and damage the armature.

Answer / pavan msh

brushes used in dc machines are mostly made of carbon bcz carbon is of low cost and also a good conductor

difference between substation & grid substation?

2 Answers   GMR,

---

why dc series motor has high starting torque

2 Answers  

---

Pl. share your experience about industrial-electronics repair of machine tool.

0 Answers  

---

In what situations relays are used in Circuit breaker? In Above what rating of Circuit breaker the relays are used? Why relays are not used for CB like MCB?

0 Answers   Elektrotek,

---

On which side, taps are provided in tap changing transformers and why?

2 Answers  

---

srij i need the relationship b/w KW AND KWH and with an electrical example. plz send if u can?

4 Answers  

---

how to calculate ups and battery rating

2 Answers  

---

where we use stardelta starter and dol starter

4 Answers   HCL,

---

What Is Connection APFC Panel In Compony.

0 Answers  

---

how to choose the cable size for 100A(is there any formula please update)

6 Answers  

---

define excitaton voltage and excitation current?

2 Answers   Allied Group,

---

is it possible to minimize the copper loss?

2 Answers   Coal India, TATA,

---