Email
Chat with tutors
Login
Ask Questions, Get Answers
Menu
X
home
ask
tuition
questions
practice
papers
mobile
tutors
pricing
X
Recent questions tagged physics
Questions
A battery is supplying power to a tape-recorder by cable of resistance $0.02\Omega$. If the battery is generating $50W $ at $5V$, the power received by the tape-recorder is:
jeemain
physics
current-electricity
cbse
class12
ch5
electrical-energy-and-power
easy
asked
Feb 10, 2014
by
thanvigandhi_1
1
answer
Calculate the mean free path in $Cu$ at room temperature $300K$, if the number density of free electrons is $8.5 \times 10^{28}/m^3$ and resistivity $r = 1.7 \times 10^{-8} mho-m$. Given $k = 1.38 \times 10^{-23} J/K \: and\: 1A = 10^{-10} m$
jeemain
physics
current-electricity
cbse
class12
ch5
electric-current-concepts
medium
asked
Feb 10, 2014
by
thanvigandhi_1
1
answer
A capacitor is charged and then made to discharge through a resistance. The time constant is $ \tau$. In what time will the potential difference across the capacitor decrease by 10%
jeemain
physics
electrostatic-potential-and-capacitance
cbse
class12
ch3
charging-and-discharging-of-capacitors
easy
asked
Feb 10, 2014
by
thanvigandhi_1
1
answer
This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements.\[\] Statement- I: In a meter bridge experiment, the null point for the unknown resistance is measured. Now, the resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at the same point as before by decreasing the value of the standard resistance. \[\] Statement- II: Resistance of a metal increases with temperature.
jeemain
physics
current-electricity
cbse
class12
ch5
meter-bridge-and-potentiometer-instrumentation
easy
asked
Feb 10, 2014
by
thanvigandhi_1
1
answer
A constant voltage is applied to the two ends of a uniform metallic wire. Some heat is produced in it. The heat developed is doubled if
jeemain
physics
current-electricity
cbse
class12
ch5
electrical-energy-and-power
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements. \[\] Statement- I: Electrons in a conductor have no motion in the absence of a potential difference across it. \[\] Statement- II: The electric field inside the static conductor is always zero.
jeemain
physics
current-electricity
cbse
class12
ch5
electric-current-concepts
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 3. The resistance of each edge is R
jeemain
physics
current-electricity
cbse
class12
ch5
equivalent-resistance
difficult
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 2. The resistance of each edge is R
jeemain
physics
current-electricity
cbse
class12
ch5
equivalent-resistance
difficult
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Find the resistance of the wire frame shaped as a cube when measured between the points 1 and 7. The resistance of each edge is R
jeemain
physics
current-electricity
cbse
class12
ch5
equivalent-resistance
difficult
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Two capacitors $C_1$ and $C_2$ are charged to $120\: V$ and $ 200\: V$ respectively. It is found that by connecting them together the potential on each one can be made zero. Then:
jeemain
physics
current-electricity
cbse
class12
ch5
equivalent-resistance
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements. \[\] Statement- I: Higher the range, greater is the resistance of ammeter. \[\] Statement- II: To increase the range of ammeter, additional shunt needs to be used across it.
jeemain
physics
current-electricity
cbse
class12
ch5
meter-bridge-potentiometer-and-instumentation
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
The supply voltage to a room is $120\: V\: DC$. The resistance of the lead wires is $6 \Omega$. A $60\: W$ bulb is already switched on. What is the decrease of voltage across the bulb, when a $240\: W$ heater is switched on in parallel to the bulb?
jeemain
physics
current-electricity
cbse
class12
ch5
electrical-energy-and-power
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
In an $LCR$ circuit as shown below both switches are open initially. Now switch $S1$ is closed, $S2$ kept open. ($q$ is charge on the capacitor and $ \tau = RC$ is capacitive time constant). Which of the following statement is correct?
jeemain
physics
electromagnetic-induction
cbse
class12
ch6
inductance
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Resistance of a given wire is obtained by measuring the current flowing in it and the voltage difference applied across it. If the percentage errors in the measurement of the current and the voltage difference are 3% each, then error in the value of resistance of the wire is
jeemain
physics
current-electricity
cbse
class12
ch5
ohms-law
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Two electric bulbs marked $25W – 220V$ and $100W – 220V$ are connected in series to a $440V$ supply. Which of the bulbs will fuse?
jeemain
physics
current-electricity
cbse
class12
ch5
electrical-energy-and-power
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A resistance of $2 \Omega$ is connected across one gap of a meter-bridge and an unknown resistance, greater than $2 \Omega$, is connected across the other gap. When these resistances are interchanged, the balance point shifts by $20cm$. The unknown resistance is
jeemain
physics
current-electricity
cbse
class12
ch5
meter-bridge-and-potentiometer-instrumentation
medium
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A moving coil galvanometer of resistance $100 \Omega$ is used as an ammeter using a resistance of $ 0.1 \Omega$. The maximum deflection current in the galvanometer is $100 \mu A$. Find the current in the circuit so that the ammeter shows full scale deflection
jeemain
physics
current-electricity
cbse
class12
ch5
meter-bridge-and-potentiometer-instrumentation
medium
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A rigid container with thermally insulated walls contains a coil of $100 \Omega$ resistance with a current of $1A$. Change in internal energy after 5 min will be
jeemain
physics
current-electricity
cbse
class12
ch5
electrical-energy-and-power
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/quantities constant along the length of the conductor are
jeemain
physics
current-electricity
cbse
class12
ch5
electric-current-concepts
medium
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A capacitor $C_1$ of capacitance $1 \mu F$ and $C_2$ of capacitance $ 2 \mu F$ are separately charged by a common battery for a long time. The two capacitors are then separately discharged through equal resistors. Both the discharge circuits are connected at $t=0$. One or more of the following happen.
jeemain
physics
electrostatic-potential-and-capacitance
cbse
class12
ch3
charging-and-discharging-of-capacitors
medium
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A capacitor of capacitance $ 500 \mu F$ is connected to a battery through a $10k \Omega $resistor. Then, which of the following are true: \[\] The charge stored on the capacitor in the first $5s$ is larger than the charge stored in the next
jeemain
physics
electrostatic-potential-and-capacitance
cbse
class12
ch3
charging-and-discharging-of-capacitors
easy
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
A wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $ \Delta T$ in a time $t$. A number $N$ of similar cells are now connected in series with a wire of the same material and cross-section but of length $2L$. The temperature is raised by the same amount $ \Delta T$ in the same time. The value of $N$ is
jeemain
physics
current-electricity
cbse
class12
ch4
electrical-energy-and-power
difficult
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
In steady state, a resistor is carrying a current $i$. The power lost to the surroundings is $b(T- T_0)$. Here $b$ is a constant, $T$ is the temperature of the resistance and $T_0$ is the surrounding temperature. If the coefficient of linear expansion is $ \alpha$. The strain in the wire is
jeemain
physics
current-electricity
cbse
class12
ch4
electrical-energy-and-power
difficult
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
The length of the potentiometer wire is l. A cell of emf E is balanced at length $ \large\frac{l}{3}$ from the positive end of the wire. If the length of the wire is increased by $ \large\frac{l}{2}$, at what distance will the same cell give a balance point
jeemain
physics
current-electricity
cbse
class12
ch4
medium
meter-bridge-and-potentiometer-instrumentation
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Two wires of resistivity $\rho 1$ and $ \rho 2$ are connected in parallel. Equivalent resistivity of the combination is
jeemain
physics
current-electricity
cbse
class12
ch4
resistivity
medium
asked
Feb 8, 2014
by
thanvigandhi_1
1
answer
Initially the spheres A and B are at potential $\;V_{A}\;$ and $\;V_{B}\;$ respectively . Now sphere B is earthed by closing the switch . The potential of A will now become
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
A charged particle of mass m and charge q is released from rest from the position $\;(x_{0} ,0)\;$ in a uniform electric field $\;E_{0} \hat{j}\;.$ The angular momentum of particle about origin
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-field
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
An electric dipole is placed perpendicular to an infinite line of charge at some distance as shown in figure . Identify the correct statement
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-flux-and-dipole
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Potential due to a system at polar coordinates $\;(r , \theta)\;$ is given by $\;\large\frac{\alpha \;cos \theta}{r^2}\;$ Find the magnitude of electric field at that point if $\;\alpha=3 Vm^2\;,(r , \theta)=(\sqrt{3} ,tan^{-1} \large\frac{1}{\sqrt{2}}). $
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-field
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Find potential difference $\;V_{AB}\;$ between $\;A(0,0,0)$ and $\;B(1m ,1m, 0)\;$ in an electric field $\;\overrightarrow{E}=y \hat{i}+x \hat{j}$
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatic-potential
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
A uniform electric field exists in x -y plane. The potential of points $\;A (2m ,2m) , B (-2m ,2m)\;and\; C(2m ,4m)\;$ are 4V , 16V and 12V respectively . The electric field is
jeemain
physics
class12
unit11
electrostatics
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
The electric field on the axis of a dipole of dipole moment $\;\overrightarrow{P}\;$ at a distance x from the line joining the charges and $\;(x > > d)\;$
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-flux-and-dipole
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
There are four concentric shells A , B , C ,D of radii a , 2a ,3a and 4a respectively . Shells B and D are given charges +q and -q respectively . Shell C is now earthed . The potential difference $\;V_{A}-V_{C}\;$ is
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
If the electric potential of the inner shell is 10V and that of the outer shell is 5V , then the potential at the centre will be
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Potential difference between centre and surface of the sphere of radius R and $\rho$ uniform volume charge density within it will be
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Three concentric matallic shells A , B and C of radii R , 2R and 3R have surface charge densities $\;\sigma , -\sigma\;and\;\sigma\;$ respectively . Find the potential difference between A & C
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Two concentric conducting spheres of radii R and 2R are carrying charges Q and -2Q respectively . If the charge on inner sphere is doubled the potential difference between the two spheres will becomes
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatics-of-conductors
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Four point charges $\;+1 \mu C ,+1 \mu C,-1 \mu C-1 \mu C\;$ are placed at the four consecutive corners of a square of side 0.1m . What is the magnitude of electric field at E as shown in figure .
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-field
medium
asked
Feb 7, 2014
by
yamini.v
1
answer
Two wires of resistivity $\rho 1$ and $\rho 2$ are connected in series. Equivalent resistivity of the combination is
jeemain
physics
current-electricity
cbse
class12
ch4
resistivity
medium
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
A $4 \mu F$ capacitor and a 2.5MW resistor are connected in series with a 12V battery. Find the time after which the potential difference across the capacitor is 3 times the potential difference across the resistor.
jeemain
physics
electrostatic-potential-and-capacitance
cbse
class12
charging-and-discharging-of-capacitors
easy
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
The potential difference across the terminals of a battery is 10V when there is a current of 3A in the battery from the negative to the positive terminal. When the current is 2A in the reverse direction, the potential difference becomes 15V. The internal resistance of battery is
jeemain
physics
current-electricity
cbse
class12
ch4
easy
cells-emf-internal-resistance
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
Which of the following has the maximum resistance?
jeemain
physics
current-electricity
cbse
class12
ch4
easy
meter-bridge-and-potentiometer-instrumentation
concepts
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
Two identical batteries having emf 2.4 V and internal resistance 0.5$ \Omega$ are connected as shown. Potential Difference between A and B is
jeemain
physics
current-electricity
cbse
class12
ch4
cells-emf-internal-resistance
medium
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
Current through the 2$ \Omega$ resistor is
jeemain
physics
current-electricity
cbse
class12
ch4
kirchoffs-law-wheatstone-bridge
easy
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
A piece of copper and another of silicon are cooled from room temperature to 75K. The resistance of
jeemain
physics
current-electricity
cbse
class12
ch4
electric-current-conceptseasy
asked
Feb 6, 2014
by
thanvigandhi_1
1
answer
A charge Q is placed at a distance $\;\large\frac{a}{2}\;$ above the centre of a horizontal , square surface of edge a as shown in figure . Find the flux of the electric field through the square surface
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
electric-flux-and-dipole
medium
asked
Feb 6, 2014
by
yamini.v
1
answer
Calculate the potential energy of the system shown in figure
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatic-potential-energy-of-a-system-of-charges
medium
asked
Feb 6, 2014
by
yamini.v
1
answer
An infinite number of charges each numerically equal to q and of the same sign are placed along the x-axis at $\;x=1 ,2 ,4 ,8----\;.$ Find elctric potential at $\;x=0$
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatic-potential-energy-of-a-system-of-charges
medium
asked
Feb 6, 2014
by
yamini.v
1
answer
Two point charges $\;q_{1}$ and $\;q_{2}$ are placed at a certain distance d from each other . The interacting force between them is F . Now both charges kept in oil of relative permittivity 5 . What is the new value of force between them
jeemain
physics
class12
ch1
electrostatics
electric-charges-and-fields
coulomb-law
medium
asked
Feb 6, 2014
by
yamini.v
1
answer
At a certain distance from a point charge , the field intensity is $\;500 V/m\;$ and the potential is 1500 V . The magnitude of charge is
jeemain
physics
class12
ch2
electrostatics
electrostatic-potential-and-capacitance
electrostatic-potential
medium
asked
Feb 6, 2014
by
yamini.v
1
answer
Page:
« prev
1
...
381
382
383
384
385
386
387
...
400
next »
Home
Ask
Tuition
Questions
Practice
Your payment for
is successful.
Continue
...