A condenser in series with a resistor is connected through a switch to a battery of negligible internal resistance and having an emf of `12 V`. One second after closing the switch, the condenser is found to have a potential difference of `6V`. The time constant of the system isA. `2 s`B. `(1)/(log_(e) 2)`C. `log_(e)2`D. `log_(e) ((1)/(2))`

A condenser in series with a resistor is connected through a switch to

1.	A condenser in series with a resistor is connected through a switch to a battery of negligible internal resistance and having an emf of `12 V`. One second after closing the switch, the condenser is found to have a potential difference of `6V`. The time constant of the system isA. `2 s`B. `(1)/(log_(e) 2)`C. `log_(e)2`D. `log_(e) ((1)/(2))`
Answer» Correct Answer - B `q = q_(0)(1-e^(-t//Rc))`, `t = 1 "second"` `CV = CV_(0)(1-e^(-t//Rc)), (1)/(2) = e^(-t//Rc)` `ln 2 = (1)/(Rc)lne , RC = (1)/(ln 2)`

Discussion

No Comment Found

Related InterviewSolutions

Two circular, similar, coaxial loops carry equal currents in the same direction. If the loops are brought nearer, what will happen?A. Current will increase in each loopB. Current will decrease in each loopC. Current will remain same in each loopD. Current will increase in one and decrease in the other
A conducting rod of length `2l` is rotating with constant angular speed `w` about its perpendicular bisector. A uniform magnetic field `B` exists parallel to the axis of rotation. The e.m.f. induced between two ends of the rod is A. `B omega l`B. `(1)/(2)B omega l^(2)`C. `(1)/(8)B omega l^(2)`D. Zero
An inductor of `2` henry and a resistance of `10` ohms are connected in series with a battery of `5` volts. The initial rate of change of current isA. `0.5 amp//sec`B. `2.0 amp//sec`C. `2.5 amp//sec`D. `0.25 amp//sec`
A thin wire of length `L` is connected to two adjacent fixed points and carries a current `I` in the clockwise direction , as shown in the figure. When the system is put in a uniform magnetic field of strength `B` going into the plane of the paper , the wire takes the shape of a circle . The tension in the wire is A. `IBL`B. `(IBL)/(pi)`C. `(IBL)/(2pi)`D. `(IBL)/(4pi)`
A short-circuited coil is placed in a time-varying magnetic field. Electrical power is dissipated due to the current induced in the coil. If the number of turns were to be quadrupled and the wire radius halved, the electrical power dissipated would be
A physicist works in a laboratory where the magnetic field is `2T`. She wears a necklace enclosing area `0.01 m^(2)` in such a way that the plane of the necklace is normal to the field and is having a resistance `R=0.01Omega`. Because of power failure, the field decays to `1T` in time `10^(-3)` seconds. The what is the total heat produced in her necklace?`(T=tesla)`A. `10J`B. `20J`C. `30J`D. `40J`
a physicist works in a laboratory where the magnetic field is `2T`. She wears a necklace enclosing of an area `100 cm^(2)` of field and having a resistance of `0.1 Omega`. Because of power failure, the field decays to `1 T` in millisecond. The electric charge circulated in the necklace assuming that the magnetic field is perpendicular to area covered by the necklace isA. `0.01 C`B. `0.001 C`C. `0.1 C`D. `1.0 C`
The linear loop has an area of `5 xx 10^(-4)m^(2)` and a resistance oof `2 Omega`. The larger circular loop is fixed and has a radius of `0.1m`. Both the loops are concentric and coplanner. The smaller loop is rotated with an angular velocity `omegarads^(-1)` about its dismeter. The magnetic flux with the smaller loop is A. `2pi xx 10^(-6) "weber"`B. `pi xx 10^(-9) "weber"`C. `pi xx 10^(-9) cos omega t "weber"`D. zero
A non-conducting disk of radius `R` is rotating about its own axis with constant angular velocity `omega` in a perpendicular uniform magnetic field `B` as shown in figure. The emf induced between centre and rim of disk is A. `pi omega B R^(2)`B. `omega B R^(2)`C. `pi omega R//2`D. `omega B R^(2)//2`
A non-conducting disk of radius `R` is rotating about its own axis with constant angular velocity `omega` in a perpendicular uniform magnetic field `B` as shown in figure. The emf induced between centre and rim of disk is A. `(B omega R^(2))/(2)`B. `B omega R^(2)`C. ZeroD. `(B omega R^(2))/(3)`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment