Browse Questions

Which of these is correct for each pair of statements?  Statement 1: $40W$ tube light appears brighter than a $40W$ bulb. Statement2: Light sources having same power rating appear to glow equally brightly

$\begin {array} {1 1} (A)\;Both \: statements\: are\: true.\: Statements\: 2\: is\: a\: correct \: explanation \: for \: statement\: 1 \\ (B)\; Both \: statements\: are\: true.\: Statements\: 2 \: is \: not\: a \: correct\: explanation\: for\: statement\: 1 \\ (C)\; Statement\: 1\: is\: true,\: statement\: 2 \: is \: false \\ (D)\;Statement \: 1\: is\: false, \: statements \: 2\: is \: false \end {array}$

Here, one must consider the emission spectra of both the sources.
In tube light, the majority of the radiation comes in the visible region. Whereas,
In the light bulb, considerable radiation occurs in UV and IR range resulting in less brightness.
Ans : (D)
edited Mar 14, 2014