electricity
In how many different ways three 1 Ω resistances can be combined?
3
4
5
6
Two wires A and B of equal masses and of the same metals are taken. The diameter of the wire A is half the diameter of the wire B. If the resistance of A is 24 Ω then find the resistance of wire B?
0.5
1
1.5
3
If 400 Ω resistance is made by adding four 100 Ω resistance of tolerance 5%, then the tolerance of the combination is
5%
10%
15%
20%
Resistance n, each of r Ω, when connected in parallel give an equivalent resistance of R Ω. If these resistances were connected in series, the combination would have a resistance in Ω, equal to
n^2R
R / n^2
R / n
nR
A cylindrical wire is stretched to increase its length b 10 %. What is the percentage increase in resistance?
10%
41%
1%
21%
A copper wire is stretched to make it 0.2%. What is the percentage change in its resistivity?
0.4%
2%
4%
none of these
A steel wire is stretched to make it 0.2% longer. What is the percentage change in its resistance?
4%
0.4%
2%
0.2%
i1+i2
i2+i3
i1+i3
i1-i2+i3
In a Wheatstone bridge, if the galvanometer shows zero deflection, the unknown resistance will be____ Ω. (Given P = 1000 Ω, Q = 10000 Ω and R = 20 Ω)
2000 ohm
10 ohm
200 ohm
100 ohm
If 6.25 × 1018 electrons flow through a given cross section in unit time, then the current is ____. (charge of an e- is 1.6 × 10-19 C)
10A
1A
3.9A
1mA
If a potential difference of 6 V is applied across a conductor of length 0.12 m, electron mobility is 5.6 x 10-6 m2 V-1 s-1, then the drift velocity of electrons will be ____.
2.8 x 10-4 m s-1
0.28 x 10-4 m s-1
28 x 10-4 m s-1
8.2×10−4ms−1
For driving a current of 3 A for 5 min in an electrical circuit, 900 J of work is to be done. Then the emf of the source in the circuit will be ____
1v
3v
2v
4v
In potentiometer, a balance point is obtained when ____.
The emf of the battery becomes equal to the emf of the experimental cell.
The potential difference of the wire between the positive end of the battery to jockey becomes equal to the emf of the experimental cell.
The potential difference of the wire between the positive point of the cell and the jockey becomes equal to the emf of the battery.
The potential difference across the potentiometer wire becomes equal to the emf of the battery.
If two similar cells are connected first in series, and then in parallel, then the ratio of balancing length in the potentiometer wire will be:
2:1
1:2
1:4
4:1
If in the experiment of Wheatstone bridge, the battery and galvanometer are interchanged, then balance points will ____.
change
remain unchanged
depend on internal resistance of the cell
depend on the emf of the battery
{"name":"electricity", "url":"https://www.quiz-maker.com/QZNW2QOG","txt":"In how many different ways three 1 Ω resistances can be combined?, Two wires A and B of equal masses and of the same metals are taken. The diameter of the wire A is half the diameter of the wire B. If the resistance of A is 24 Ω then find the resistance of wire B?, If 400 Ω resistance is made by adding four 100 Ω resistance of tolerance 5%, then the tolerance of the combination is","img":"https://cdn.poll-maker.com/55-2191501/screenshot-37-.png?sz=1200-01757035290387805300"}