KCET · Physics · Electrostatics
A straight wire of length \( 50 \mathrm{~cm} \) carrying a current of \( 2.5 \mathrm{~A} \) is suspended in mid-air by a uniform magnetic field of \( 0.5 \mathrm{~T} \) (as shown in figure). The mass of the wire is \( \left(\mathrm{g}=10 \mathrm{~m} \mathrm{~s}^{-2}\right) \)
- A \( 62.5 \mathrm{gm} \)
- B \( 250 \mathrm{gm} \)
- C \( 125 \mathrm{gm} \)
- D \( 100 \mathrm{gm} \)
Answer & Solution
Correct Answer
(A) \( 62.5 \mathrm{gm} \)
Step-by-step Solution
Detailed explanation
Given, the wire is suspended in mid air by uniform magnetic field. Now,
\(\Rightarrow F=m g \)
\(\Rightarrow I B l=m g \)
\(\Rightarrow m=\frac{I B l}{g} \)
\(\Rightarrow m=\frac{2.5 \times 0.5 \times\left(50 \times 10^{-2}\right)}{10}=0.625 \mathrm{~kg}=62.5 \mathrm{~g}\)
Thus, mass of wire is \( 62.5 \mathrm{~g} \).
\(\Rightarrow F=m g \)
\(\Rightarrow I B l=m g \)
\(\Rightarrow m=\frac{I B l}{g} \)
\(\Rightarrow m=\frac{2.5 \times 0.5 \times\left(50 \times 10^{-2}\right)}{10}=0.625 \mathrm{~kg}=62.5 \mathrm{~g}\)
Thus, mass of wire is \( 62.5 \mathrm{~g} \).
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
- For the arrangement of capacitors as shown in the circuit, the effective capacitance between the points \( A \) and \( B \) is (capacitance of each capacitor is \( 4 \mu \mathrm{F} \) )
KCET 2018 Medium - If \( \alpha \)-current gain of a transistor is \( 0.98 . \) What is the value of \( \beta \)-current gain of the transistor ?KCET 2014 Easy
- An n-type and p-type semiconductor can be obtained by respectively doping pure silicon withKCET 2026 Easy
- An electric bulb of \(60 \mathrm{~W}, 120 \mathrm{~V}\) is to be connected to 220 V source. What resistance should be connected in series with the bulb, so that the bulb glows properly?KCET 2024 Medium
- A physical quantity \( \mathrm{Q} \) is found to depend on observable \( \mathrm{x}, \mathrm{y} \) and \( \mathrm{z} \), obeying relation \( Q=\frac{x^{3} y^{2}}{z} \). The percentage error in the measurements of \( x, y \) and \( z \) are \( 1 \%, 2 \% \) and \( 4 \% \) respectively. What is percentage error in the quantity \( \mathrm{Q} \) ?KCET 2014 Medium
- A cyclotron is used to accelerate protons \(\left({ }_{1}^{1} \mathrm{H}\right)\) deuterons \(\left({ }_{1}^{2} \mathrm{H}\right)\) and \(\alpha\)-particles \(\left({ }_{2}^{4} \mathrm{He}\right)\). While exiting under similar conditions, the minimum KE is gained byKCET 2020 Medium
More PYQs from KCET
- The potential of the electric field produced by point charge at any point \((x, y, z)\) is given by \(V=3 x^{2}+5\), where \(x, y\) are in metres and \(V\) is in volts. The intensity of the electric field at \((-2,1,0)\) isKCET 2007 Easy
- In a radioactive decay, an element \(\mathrm{z}^{\mathrm{X}}\) emits four \(\alpha\)-particles, three \(\beta\)-particles and eight gamma photons. The atomic number and mass number of the resulting final nucleus areKCET 2012 Medium
- In a two slit experiment with monochromatic light fringes are obtained on a screen placed at some distance from the slits. If the screen is moved by \(5 \times 10^{-2} \mathrm{~m}\) towards the slits, the change in fringe width is \(3 \times 10^{-5} \mathrm{~m}\). If separation between the slits is \(10^{-3} \mathrm{~m}\), the wavelength of light used isKCET 2008 Medium
- Resonance effect is not observed inKCET 2019 Easy
- Consider the following statements Statement 1 : \(\lim _{x \rightarrow 1} \frac{a x^{2}+b x+c}{c x^{2}+b x+a}\) is 1 (where \(a+b+c \neq 0\) ).
Statement \(2: \lim _{x \rightarrow 2} \frac{\frac{1}{x}+\frac{1}{2}}{x+2}\) is \(\frac{1}{4}\).KCET 2021 Medium - A cyclotron is used to accelerateKCET 2015 Medium