Question

420 J of energy supplied to 10 g of water will raise its temperature by nearly

• A. l${}^{\circ }$C
• B. 4.2${}^{\circ }$C
• C. 10${}^{\circ }$C
• D. 42${}^{\circ }$C

Answer 1

Answer: (C)

$Q=mc\Delta \theta$
or $420=10\times 1^{-3}\times (4.2\times 1000)\Delta \theta$
(Specific heat of water= 4.2 $\times kJk{g}^{-1}{C}^{-1}$
$\Delta \theta =\frac{420}{10\times 10^{-3}4200}=10^{\circ }C$