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In permanent magnets, the desired features are

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Electrical contact materials used in switches, brushes and relays must possess 

 (A) high thermal conductivity and high melting point 

(B) Low thermal conductivity and low melting point 

 (C) High thermal conductivity and low melting point 

(D) Low thermal conductivity and high melting point.

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Electrical contact materials used in switches, brushes and relays must possess high thermal conductivity and high melting point 

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