MCQ
While working on a physics project at school physics lab, you require a $4 \,\mu F$ capacitor in a circuit across a potential difference of $1 \,kV$. Unfortunately, $4 \,\mu F$ capacitors are out of stock in your lab but $2 \,\mu F$ capacitors which can withstand a potential difference of $400 \,V$ are available in plenty. If you decide to use the $2 \,\mu F$ capacitors in place of $4 \,\mu F$ capacitor, minimum number of capacitors required are
  • A
    $16$
  • $18$
  • C
    $20$
  • D
    $12$

Answer

Correct option: B.
$18$
b
(b)

$C_{A B}=\frac{2}{3}$

Total number of benches $=\frac{{ }^2 \not 4 \times 3}{\not 2}=6$

Total number of capacitors $=6 \times 3=18$

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

Similar questions

A thin prism $P_1$ with an angle $6^{\circ}$ and made of glass of refractive index $1.54$ is combined with another prism $P _2$ made from glass of refractive index $1.72$ to produce dispersion without average deviation. The angle of prism $P_2$ is $........{}^{\circ}$
This question has Statement $- 1$ and Statement$- 2$. Of the four choices given after the statements, choose the one that best describes the two statements. 
Statement $- 1$ : Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals.
Statement $- 2$ : The state of ionosphere varies from hour to hour, day to day and season to season.
Dynamo is a device for converting
A particle is projected with a velocity ( $10\ m/s$ ) along $y-$ axis from point $(2, 3)$ . Magnetic field of $\left( {3\hat i + 4\hat j} \right)$ Tesla exist uniformly in the space. Its speed when particle passes through $y-$ axis for the third time is : (neglect gravity)
Given below are two statements:

Statement $I$ : A uniform wire of resistance $80\,\Omega$ is cut into four equal parts. These parts are now connected in parallel. The equivalent resistance of the combination will be $5\,\Omega$.

Statement $II :$ Two resistance $2\,R$ and $3\,R$ are connected in parallel in a electric circuit. The value of thermal energy developed in $3\,R$ and $2\,R$ will be in the ratio $3:2.$

In the light of the above statements, choose the most appropriate answer from the options given below

Two metallic charged spheres whose radii are $20\,cm$ and $10\,cm$ respectively, have each $150\,micro - coulomb$ positive charge. The common potential after they are connected by a conducting wire is
A very long bar magnet is placed with its north pole coinciding with the centre of a circular loop carrying as electric current i. The magnetic field due to the magnet at a point on the periphery of the wire is B. The radius of the loop is a. The force on the wire is:
A proton (or charged particle) moving with velocity $v$ is acted upon by electric field $E$ and magnetic field $B$. The proton will move undeflected if
Wavelength of an electron having energy $10\ keV$ is $......... A^0$:
A uniform wire of resistance R is uniformly compressed along its length, until its radius becomes n times the original radius. Now resistance of the wire becomes