Assertion : A thin stainless steel needle can lay floating on a s… - Vidyadip

MCQ

$Assertion :$ A thin stainless steel needle can lay floating on a still water surface.
$Reason :$ Any object floats when the buoyancy force balances the weight of the object

A
If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
✓
If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
C
If the Assertion is correct but Reason is incorrect.
D
If both the Assertion and Reason are incorrect.

✓

Answer

Correct option: B.

If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.

b
Assertion and Reason are correct. But Reason does not explain Assertion. Explanation of Assertion is that it is the surface tension of the water surface which is balancing the weight of the steel needle.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

JEE STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

Two identical straight wires are stretched so as to produce $6$ beats per second when vibrating simultaneously. On changing the tension in one of them, the beat frequency remains unchanged. Denoting by ${T_1},\,{T_2}$, the higher and the lower initial tensions in the strings, then it could be said that while making the above change in tension

A transformer has an efficiency of $80\%$ and works at $10 V$ and $4 \ kW.$ If the secondary voltage is $240 V,$ then the current in the secondary coil is $:$

Flux $\phi $ (in weber) in a closed circuit of resistance $10\, ohm$ varies with time $t$ (in $sec$) according to the equation $\phi = 6t^2 - 5t +1$ . What is the magnitude of the induced current at $t = 0.25\, s$ ?.....$A$

If $\vec P = \vec Q$ then which of the following is NOT correct

The height of a transmitting antenna at the top of a tower is $25 \; m$ and that of receiving antenna is, $49 \; m$. The maximum distance between them, for satisfactory communication in LOS (Line of Sight) is $K \sqrt{5} \times 10^{2} \; m$. The value of $K$ is $\dots$ [Assume radius of Earth is $64 \times 10^{+5} \; m$ ] (Calculate upto nearest integer value)

The electric intensity $E$, current density $j$ and specific resistance $k$ are related to each other by the relation

One end of a horizontal thick copper wire of length $2 L$ and radius $2 R$ is welded to an end of another horizontal thin copper wire of length $L$ and radius $R$. When the arrangement is stretched by a applying forces at two ends, the ratio of the elongation in the thin wire to that in the thick wire is :

A solid body rotates about a fixed axis such that its angular velocity depends on $\theta$ as $\omega=k \theta^{-1}$ where $k$ is a positive constants. At $t=0, \theta=0$, then time dependence of $\theta$ is given as ..........

The metallic surface is illuminated with monochromatic light of wavelength $\lambda $ and stopping potential for photoelectric current is $5V_0$. When the same metallic surface is illuminated with a light of wavelength $2\lambda $ , the stopping potentials is $V_0$. What is the threshold wavelength for the surface ?

Which of the following statements concerning the depletion zone of an unbiased $PN $ junction is (are) true