Question

Statement 1 : The temperature coefficient of resistance is positive for metals and negative for $p$ -type semiconductor
Statement 2 : The effective charge carriers in metals are negatively charged whereas in $p$ -type semiconductor, they are positively charged

• A. Statement-1 is true, Statement-2 is false
• B. Statement-1 is false, Statement-2 is true
• C. Statement-1 is true, Statement-2 is true and Statement-2 is a correct explanation for Statement-1
• D. Statement-1 is true, Statement-2 is true but Statement-2 is not a correct explanation for Statement-1

Answer 1

Answer: (D)

When the temperature increases in metal, the kinetic energy of electron also increases. With increase in kinetic energy, the number of collision between electron themselves and between electrons and atom or ions increases. This increases the resistivity of metal. While in case of semiconductor more number of slectron jumps to conduction band with increase in temperature because of which its resistivity decreases. Because of these reasons metal have positive temperature coefficient and semiconductor have negative temperature coefficient