JEE Mains · Physics · STD 12 - 5. Magnetism and matter
Given below are two statements; one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A:\) Electromagnets are made of soft iron. Reason \(R:\) Soft iron has high permeability and low retentivity. In the light of above, statements, choose the most appropriate answer from the options given below.
- A \(A\) is not correct but \(R\) is correct
- B Both \(A\) and \(R\) are correct and \(R\) is the correct explanation of \(A\)
- C Both \(A\) and \(R\) are correct but \(R\) is NOT the correct explanation of \(A\)
- D \(A\) is correct but \(R\) is not correct
Answer & Solution
Correct Answer
(B) Both \(A\) and \(R\) are correct and \(R\) is the correct explanation of \(A\)
Step-by-step Solution
Detailed explanation
Electromagnets are made of soft iron because it has high permeability and low retentivity. So, Both \(A\) and \(R\) are correct and \(R\) is the correct explanation of \(A\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- A particle starts simple harmonic motion from the mean position. Its amplitude is \(a\) and total energy \(E\). At one instant its kinetic energy is \(3E/4.\) Its displacement at that instant isJEE Mains 2021 Medium
- A submarine \((A)\) travelling at \(18\, km/hr\) is being chased along the line of its velocity by another submarine \((B)\) travelling at \(27\, km/hr\). \(B\) sends a sonar signal of \(500\, Hz\) to detect \(A\) and receives a reflected sound of frequency \(v\). The value of \(v\) is close to ... \(Hz\) (Speed of sound in water \(= 1500\, ms^{-1}\))JEE Mains 2019 Hard
- In the given circuit, the voltage across load resistance \(\left(R_L\right)\) is _______.
JEE Mains 2024 Hard - Consider a parallel plate capacitor of area A (of each plate) and separation 'd' between the plates. If \(E\) is the electric field and \(\varepsilon_0\) is the permittivity of free space between the plates, then potential energy stored in the capacitor isJEE Mains 2025 Easy
- A physical quantity \(Q\) is related to four observables \(a, b, c, d\) as follows :
\(\mathrm{Q}=\frac{\mathrm{ab}{ }^4}{\mathrm{~cd}}\)
where, \(\mathrm{a}=(60 \pm 3) \mathrm{Pa} ; \mathrm{b}=(20 \pm 0.1) \mathrm{m} ; \mathrm{c}=(40 \pm 0.2) \mathrm{Nsm}^{-2}\) and \(\mathrm{d}=(50 \pm 0.1) \mathrm{m}\), then the percentage error in Q is \(\frac{x}{1000}\), where \(x=\) ________ .JEE Mains 2025 Medium - A thin prism of angle \(6^{\circ}\) and refractive index for yellow light \(\left(n_{Y}\right) 1.5\) is combined with another prism of angle \(5^{\circ}\) and \(n _{ Y }=1.55\). The combination produces no dispersion. The net average deviation ( \(\delta\) ) produced by the combination is \(\left(\frac{1}{x}\right)^{\circ}\). The value of \(x\) is.......
JEE Mains 2022 Medium
More PYQs from JEE Mains
- The urns \(A, B\) and \(C\) contain \(4\) red, \(6\) black;\(5\) red,\(5\) black and \(\lambda\) red,\(4\) black balls respectively. One of the urns is selected at random and a ball is drawn. If the ball drawn is red and the probability that it is drawn from urn \(C\) is \(0.4\) then the square of the length of the side of the largest equilateral triangle, inscribed in the parabola \(y^2=\lambda x\) with one vertex at the vertex of the parabola isJEE Mains 2023 Hard
- In an ellipse, with centre at the origin, if the difference of the lengths of major axis and minor axis is \(10\) and one of the foci is at \((0, 5\sqrt 3 )\), then the length of its latus rectum isJEE Mains 2019 Hard
- Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Electromagnetic waves carry energy but not momentum.
Reason (\(\mathbf{R}\)): Mass of a photon is zero.
In the light of the above statements, choose the most appropriate answer from the options given below :JEE Mains 2025 Easy - A stone tide to a string of length \(L\) is whirled in a vertical circle with the other end of the string at the centre. At a certain instant of time, the stone is at its lowest position and has a speed \(u\). The magnitude of change in its velocity, as it reaches a position where the string is horizontal, is \(\sqrt{ x \left( u ^{2}- gL \right)}\). The value of \(x\) is .............JEE Mains 2022 Medium
- As shown in figure, a \(70\,kg\) garden roller is pushed with a force of \(\overrightarrow{ F }=200\,N\) at an angle of \(30^{\circ}\) with horizontal. The normal reaction on the roller is \(.......\,N\) \(\left(\right.\) Given \(\left.g =10\,m s ^{-2}\right)\)
JEE Mains 2023 Medium - Let \(f(x)=\int \frac{d x}{x^{\left(\frac{2}{3}\right)}+2 x^{\left(\frac{1}{2}\right)}}\) be such that \(f(0)=-26+24 \log _{ e }(2)\). If \(f (1)= a + b \log _{ e }(3)\), where \(a , b \in Z\), then \(a + b\) is equal to:JEE Mains 2026 Hard