An ammeter, voltmeter and a resistor are connected in series to a cell and the readings are noted as I and V. If another resistor R is connected in parallel with voltmeter, then
I and V increase
I increases
I and V will remain same
I decreases
One gram of copper is deposited in a copper voltameter when a current of 0.5 A flows for 30 minutes. Then, the current required to deposit 2g of silver in a silver voltmeter in the same time is (ece of copper = 3.3x10-4 gC-1, ece of silver = 1.1 x 10-4 gC-1)
4 A
6 A
3 A
5 A
C.
3 A
ECE of copper = 3.3 × 10-4 gmc-1
ECE of silver = 1.1 × 10-4 gmc-1
Time (t) = 30 min
l = 0.5 A
Deposited mass = 2 gm
m = Zlt
The amount of charge flowing per second per unit area normal to the flow is called
electrical conductivity
electrical resistivity
mobility
current density
A galvanometer of resistance G is converted into an ammeter using a shunt of resistance R. If the ratio of the heat dissipated through the galvanometer and shunt is 3 : 4, then R equals
Two bulbs of equal power are connected in parallel and they totally consume 110 W at 220 V. The resistances of each bulb is
550 Ω
440 Ω
330 Ω
880 Ω
The wire of length l is bent into a circular loop of a single turn and is suspended in a magnetic field of induction B. When a current I is passed. through the loop, the maximum torque experienced by it is
BIl2
BI2l
BIl
B2Il
A particle having charge 10 times that of the electron revolves in a circular path of radius 0.4 m with an angular speed of one rotation per second. The magnetic induction produced at the centre of the circular path is
Pick out the wrong statement among the following.
Time varying magnetic field creates an electric field
Charges in motion can exert force on a stationary magnet
Stationary charges can exert torque on a stationary magnet
A bar magnet in motion can exert force on a stationary charge
If a magnet is plugged into a coil, then the magnitude of induced emf does not depend upon
the number of turns in the coil
the medium of the core of the coil
the resistance of the coil
the strength of the magnet
If 0.1 J of energy is stored for the flow of current of 0.2 A in an inductor, then its inductance value is
5 H
0.5 H
5 mH
50 H