12th Standard Syllabus & Materials
12th Standard
TN 12th Computer Applications மின்னணு தரவு பரிமாற்றம் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications மின் - வணிக பாதுகாப்பு அமைப்புகள் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications மின்னணு செலுத்தல் முறைகள் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications மின் - வணிகம் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications திறந்த மூல கருத்துருக்கள் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications வலையமைப்பு வடமிடல் Sample Question Papers Study Material - QB365 Set A
Published on: 13/10/2020
12th Standard Physics Current Electricity English Medium Free Online Test One Mark questions 2020 - 2021
Download Tamil Nadu 12th Standard Physics question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.
Questions + Answers key
Take MCQ Physics Test1.
Potentiometer is an instrument used for the measurement of____________
current
resistance
capacitance
potential difference
2.
In the case of meter bridge manganin wire is used because it has_________
low temperature coefficient of resistance
high temperature coefficient of resistance
temperature coefficient of resistance is zero
temperature coefficient of resistance is maximum
3.
In Kirchhoff's II law the current in clockwise direction is taken as________
positive
negative
neutral
no direction
4.
Ohm's law is applicable only for_______________
complicated circuits
primary circuits
simple circuits
secondary circuits
5.
The temperature coefficient of resistance is negative for_________
for metals
ebonite
(a) and (b)
none
6.
In a carbon resistor, the third ring represents___________
powers of zeros
powers of ten
ten
infinity
7.
The transition temperature of mercury is________
4.2°C
4.2 K
2.4°C
2.4K
8.
The reciprocal of conductivity is________
specific conductance
specific resistance
resistance
conductance
9.
The unit of current density is________
Am-2
Am2
A2m-2
A-2m-2
10.
Carbon are furnaces produce temperature upto________
1500oC
2000o C
2500oC
3000oC
11.
Calculate the mobility of a free electron in an electric field of 10+2N/C.
10-4m2V-1s-1
10-5m2V-1s-1
10-3m2V-1s-1
105m2V-1s-1
12.
The resistance of the wire varies inversely as _________________.
area of cross section
resistivity
length
temperature
13.
When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________
1: n2
n2: 1
n: 1
1: n
14.
The colour code on a carbon resistor is red - red - black. The resistance of the resistor is ___________.
\(2.2\Omega \)
\(22\Omega \)
\(220\quad 2.2\Omega \)
\(2.2k\Omega \)
15.
The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.
0.2 Ω
0.5 Ω
0.8 Ω
1.0 Ω
16.
In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.
14 A
8 A
10 A
12 A
17.
A wire connected to a power supply of 230 V has power dissipation P1. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P2. The ratio \(\frac{P_2}{P_1}\) is ______.
1
2
3
4
18.
What is the value of resistance of the following resistor?
100 k Ω
10 k Ω
1 k Ω
1000 k Ω
19.
A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.
400 W
2 W
480 W
240 W
20.
The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?
2 ohm
4 ohm
8 ohm
1 ohm
1.
(a)
current
2.
(c)
temperature coefficient of resistance is zero
3.
(a)
positive
4.
(c)
simple circuits
5.
(b)
ebonite
6.
(c)
ten
7.
(b)
4.2 K
8.
(b)
specific resistance
9.
(a)
Am-2
10.
(d)
3000oC
11.
(b)
10-5m2V-1s-1
12.
(a)
area of cross section
13.
(b)
n2: 1
14.
(b)
\(22\Omega \)
15.
I = 0.2 A, R = 10 Ω, E = 2.1 V
\(I=\frac{ɛ}{R+r}\)
\(0.2=\frac{2.1}{10+r}\)
0.2 x (10 + r) = 2.1
2 + 0.2 r = 2.1
0.2 r = 2.1 - 2 = 0.1
Internal resistance, \(r=\frac{0.1}{0.2}=\frac{1}{2}\)
r = 0.5 Ω
16.
Total power = 15 x 40 + 5 x 100 + 5 x 80 + 1000
= 600 + 500 + 400 + 1000
= 2500 W
P = VI, V = 220 V
\(I=\frac{P}{V}=\frac{2500}{220}=11.363 \ A\)
≃ 12 A
17.
\(\mathrm{V}=230 \mathrm{~V} \)
\(P=\frac{V^2}{R} \text { since } \mathrm{V} \text { is same } \mathrm{P} \propto \frac{1}{R} \)
\(\frac{1}{R_2}=\frac{1}{\frac{R_1}{2}}+\frac{1}{\frac{R_1}{2}}=\frac{2}{R_1}+\frac{2}{R_1}=\frac{2+2}{R_1} \)
\(\frac{1}{R_2}=\frac{4}{R_1} \)
\(\therefore R_2=\frac{R_1}{4} \)
\(R_1=4 R_2 \)
\(\therefore \frac{P_2}{P_1}=\frac{R_1}{R_2}=\frac{4 R_2}{R_2}=4\)
18.
Brown - 1
Black - 0
Yellow - 104
(∴ R = 10 x 104 Ω = 100 kΩ)
19.
\(P=\frac{V^2}{R}=\frac{240 \times 240}{120}=480 \ W\)
20.
Resistance, \(R=\frac{V}{I}=\frac{4}{2}=2 \ ohm\)
12th Standard Syllabus & Materials
12th Standard
TN 12th Computer Applications களப்பெயர் முறைமை (DNS) Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications வலையமைப்பு எடுத்துக்காட்டுகள் மற்றும் நெறிமுறைகள் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications கணினி வலையமைப்பு ஓர் அறிமுகம் Sample Question Papers Study Material - QB365 Set A
NEW12th Standard
TN 12th Computer Applications PHP-உடன் MySQL-ஐ இணைத்தல் Sample Question Papers Study Material - QB365 Set A
Tamilnadu Stateboard 12th Standard Subjects
Maths
Chemistry
Physics
Biology
Computer Science
Business Maths and Statistics
Economics
Commerce
Accountancy
History
Computer Applications
Biology
Computer Technology
Computer Applications
Computer Science
Business Maths and Statistics
Commerce
Economics
Maths
Chemistry
Physics
Computer Technology
History
Accountancy
Tamil
English
French
Tamilnadu Stateboard Standards
