Q.1.
Carbon resistor used in electronic circuit are marked for their resistance value and tolerance by a colour scheme. A given resistor has a colour scheme brown, green and gold. It value is Ohms
-
35%
a)3.2×105 ± 5%
-
27%
b) 1.0×106 ± 10%
-
32%
c)1.0 ×106 ± 5%
-
6%
d)1.0×103 ± 5%
Q.2.
Through an electrolyte an electric current is due to drift of
-
44%
a) free electrons
-
16%
b) free electrons and holes
-
36%
c)positive and negative ions
-
5%
d)protons
Q.3.
The specific resistance of any known metal is not affected by change in
-
22%
a) temperature
-
21%
b) pressure
-
20%
c) applied magnetic field
-
37%
d) dimensions
Q.4.
A flow of 107 electrons per second in a conduction wire constitutes current of
-
25%
a)1.6×10-26 amp
-
24%
b) 1.6×1012 amp
-
38%
c)1.6×10-12 amp
-
14%
d)1.6×1026 amp
Q.5.
In the given figure equivalent resistance between P and Q will be
-
13%
a) 14/9Ω
-
31%
b) 9/14 Ω
-
42%
c) 14/3 Ω
-
13%
d) 3/14 Ω
Explanation
Q.6.
If specific resistance of a potentiometer wire is 10-7 Ωm, the current flow through it is 0.1 A and the cross-sectional area of wire is 10-6 m2 then potential gradient will be [ CBSE PMT 2001]
-
33%
a)10-2 V/m
-
20%
b) 10-4 V/m
-
34%
c) 10-6 V/m
-
13%
d)10-8 V/m
Q.7.
An electron is revolving n times per second. The charge passing in t sec is
-
32%
a) net
-
46%
b) ne/t
-
13%
c)nt/e
-
8%
d)et/n
Q.8.
A resistance wire connected in the left gap of a metre bridge balances a 10 Ω resistance in the right gap at a point which divides the bridge wire in the ratio 3 :If the length of the resistance wire is 1.5 m, then the length of 1 Ω of the resistance wire is : [ NEET 2020]
-
27%
a) 1.0×10−2 m
-
22%
b) 1.0×10−1 m
-
31%
c) 1.5×10−1 m
-
20%
d) 1.5×10−2 m
Explanation
Q.9.
The color code of a resistance is given below The values of resistance and tolerance, respectively, are [NEET 2020]
-
25%
a) 470 kΩ, 5%
-
29%
b) 47 kΩ, 10%
-
26%
c) 4.7 kΩ, 5%
-
20%
d) 470 Ω, 5%
Q.10.
The reading of ideal voltmeter in the circuit shown is
-
15%
a) 0.6V
-
36%
b) 0V
-
32%
c) 0.5V
-
17%
d) 0.4V
Explanation
Q.11.
The meter bridge shown in the balance position with P/Q=l1/l2 .
-
24%
a) Yes P/Q=(l2-l1)/(l2+l1 ).
-
31%
b) No, no null point
-
22%
c) Yes P/Q=l2/l1
-
22%
d) Yes P/Q=l1/l2 .
Q.12.
) In the circuits shown below, the readings of voltmeters and the ammeters will be
-
18%
a) V1 = V2 and i1 < i2
-
47%
b) V1 = V2 and i1 = i2
-
14%
c) V1 > V2 and i1 > i2
-
21%
d) V1 = V2 and i1 = i2
Q.13.
A carbon resistor of (47±4.7)kΩ is to be marked with rings of different colours for its identification. The colour code sequence
-
26%
a) Yellow – Green – Violet – Gold
-
52%
b) Yellow – Violet –Orange – Silver
-
15%
c) Violet – Yellow – Orange – Silver
-
6%
d) Green – Orange– Violet– Gold
Q.14.
A set of 'n' equal resistors, of value 'R' each are connected in series to a battery of emf 'E' and internal resistance 'R'. The current drawn is I. Now, the 'n' resistors are connected in parallel to the same battery. Then, the current draw from battery become 10I. The value of 'n' is
-
16%
a) 20
-
28%
b) 11
-
40%
c) 10
-
16%
d) 9
Explanation
Q.15.
A battery consists of a variable number ‘n’ of identical cells ( having internal resistance ‘r’ each) which are connected in series. The terminals of the battery are short-circuited and the current I is measured. Which of the graphs shows the correct relationship between I and n
-
20%
-
41%
b)
-
25%
c)
-
14%
d)
Q.16.
The following unbalanced Wheatstone Bridge is constructed. Calculate the output voltage across points C and D [AFMC 1999]
-
10%
a) 60 V
-
34%
b) 35 V
-
45%
c) 100V
-
11%
d) 50V
Explanation
Q.17.
A 2Ω resistor is connected in series with R Ω resistor. This combination is connected across a cell. When the potential difference across 2 Ω resistor is balanced on potentiometer wire, null point is obtained at length of 300cm. When the same procedure is repeated for R Ω resistor, null point is obtained at length 350cm, value of R is .. [AFMC 2000]
-
18%
a) 5
-
41%
b) 3.33
-
22%
c) 4.6
-
19%
d) 2.33
Explanation
Q.18.
Three bulbs of 40W, 60W and 100W are arranged in series with 220V, which bulb has minimum resistance? [AFMC 2001]
-
26%
a) 100W
-
36%
b) 40W
-
10%
c) 60W
-
28%
d) equal in all bulbs
Q.19.
The measurement of voltmeter in the following circuit is .[AFMC 2001]
-
39%
a) 6.0V
-
28%
b) 4.0V
-
17%
c) 3.4V
-
16%
d)2.4V
Q.20.
The potentiometer consists of wire of length 4m and resistance 10 立. It is connected to a cell of e.m.f 2V. The potential difference per unit length of the wire will be
-
15%
a) 10 V/m
-
28%
b) 5 V/m
-
33%
c) 2 V/m
-
24%
d) 0.5 V/m
Q.21.
An electron revolves 6×1015 times per second in a circular orbit. The current in the loop is
-
30%
a) 0.96 mA
-
36%
b) 0.96 µA
-
16%
c)28.8 A
-
18%
d)none of these
Q.22.
A 100W, 200V bulb is connected to a 160V supply. The actual power consumption would be … [AFMC 2002]
-
15%
a) 185W
-
34%
b) 100W
-
42%
b) 54W
-
10%
b) 64W
Explanation
Q.23.
The practical unit of resistance is 立. and1 立 is equal to : [AFMC 2003]
-
22%
a) 1018emu
-
39%
b) 109emu
-
31%
c) 1015emu
-
7%
d) none of these
Explanation
Q.24.
Kirchoff’s I and II laws are based on conservation of [AFMC 2003]
-
28%
a) Energy and Charge respectively
-
49%
b) Charge and energy respectively
-
15%
c) mass and charge respectively
-
8%
d) none of these above
Q.25.
Ohms Law is not obeyed by : [AFMC 2003]
-
6%
a) electrolytes
-
24%
b) discharge tube
-
30%
c) vacuum tube
-
39%
d) all of the above
Q.26.
A wire is cut in to 4 pieces, which are put together by sides to obtain one conductor. If the original resistance of wire was R, the resistance of the bundle will be: [AFMC 2005]
-
25%
a) R/4
-
27%
b) R/8
-
37%
c) R/16
-
12%
d) R/32
Explanation
Q.27.
In the circuit shown in the figure the potential difference between X and Y will be [AFMC 2007]
-
39%
a) zero volts
-
21%
b) 20V
-
16%
c) 60V
-
24%
d) 120V
Q.28.
The length of the wire is doubled, its conductance will [AFMC 2007]
-
23%
a) remain unchanged
-
33%
b) be halved
-
27%
c) be doubled
-
17%
d) be quadrupled
Q.29.
The physical quantity having the dimensions [M-1 L-3T3 A2 is [AFMC 2008]
-
17%
a) resistance
-
28%
b) resistivity
-
38%
c) electrical conductivity
-
17%
d) electromotive force
Explanation
Q.30.
A battery of emf 10 V and internal resistance 3Ω is connected to a resistor. The current in the circuit is 0.5 A. The terminal voltage of the battery when the circuit is closed is [AFMC 2008]
-
5%
a) 10V
-
27%
b) 0V
-
30%
c) 1.5V
-
38%
d) 8.5V