In comparing e.m.f two cells with the help of a potentiometer, at the balance point, the current flowing through the wire is taken from ____.
one of these cells
both of these cells
the battery in the circuit
none of these
A battery of 20 cells (each having e.m.f. 1.8 volt and internal resistance 0.1 ohm) is charged by 220 volts and the charging current is 15A. The resistance to be put in the circuit is ____.
10.27 ohms
12.27 ohms
8.62 ohms
16.24 ohms
A primary cell has e.m.f.2 volts. When short circuited it gives a current of 4 amperes, Its internal resistance in ohms will be ____.
0.5
2
5
8
In our houses all electrical devices operate on 220V. It implies that ____.
they are connected in parallel
they are connected in series
they all have currents of equal values
they all have the same resistance
A current of 5 amperes is passing through a metallic wire of cross-section area 4 x 10-6 m2. If the density of the charge carrier in the wire is 5 x 1026/m3, the drift velocity of the electrons is ____.
1/8 m/s
1/16 m/s
1/64 m/s
1/78 m/s
If a resistance 5 is connected in the left gap of a meter bridge and 15 in the other gap then position of balancing point is
10 cm
20 cm
25 cm
75 cm
If three 2 ohms resistance are connected to from a triangle, then equivalent resistance between any two corners is ____.
6 ohms
2 ohms
¾ ohms
4/3 ohms
A potentiometer wire, 10 m long has resistance 40 ohms. If it is put in series to a resistance 760 ohms and connected to a 2 volts battery, then potential gradient in the wire is ____.
1 x 10-2 volt/m
1 x 10-3 volt/m
1 x 10-4 volt/m
1 x 10-5 volt/m
The value of current i in the given circuit is ____.
zero
5 amp
7 amp
11 amp
How much work is done in moving a charge of coulombs from a point at 118 volts to a point at 128 volts?
10 J
20 J
1/10 J
None of these