Day 138: JEE Mains Physics

Ray Optics. This type asked 2 times: 2021 Paper 19, 25 Jul 2022. This one: 25 Jul 2022 See all 2 of this type

Motion in a Straight Line. This type asked 2 times: 26 Jun 2022, 29 Jun 2022. This one: 29 Jun 2022 See all 2 of this type

Thermal Properties of Matter. This type asked 2 times: 2021 Paper 7, 29 Jun 2022. This one: 29 Jun 2022 See all 2 of this type

23

As per the given figure, two plates $A$ and $B$ of thermal conductivity $K$ and $2\text{ }K$ are joined together to form a compound plate. The thickness of plates are $4.0\text{ }cm$ and $2.5\text{ }cm$ respectively and the area of cross-section is $120{\text{ }cm}^{2}$ for each plate. The equivalent thermal conductivity of the compound plate is $\left( 1 +\frac{5}{\alpha} \right)K$, then the value of $\alpha$ will be

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Electromagnetic Induction. This type asked 2 times: 2021 Paper 26, 27 Jun 2022. This one: 27 Jun 2022 See all 2 of this type

Laws of Motion. This type asked 2 times: 2021 Paper 19, 27 Jun 2022. This one: 27 Jun 2022 See all 2 of this type

4

A system of two blocks of masses $m = 2\text{ }kg$ and $M = 8\text{ }kg$ is placed on a smooth table as shown in figure. The coefficient of static friction between two blocks is 0.5. The maximum horizontal force $F$ that can be applied to the block of mass $M$ so that the blocks move together will be:

1. A.
   $9.8\text{ }N$
2. B.
   $39.2\text{ }N$
3. C.
   $49\text{ }N$
4. D.
   $78.4\text{ }N$

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