A bar magnet is divided into two pieces, which of the following statement is correct?
คำตอบ
(A)
two new magnets are created
3
Consider the wave equation y = 5mm sin [1cm\(^{-1}\)x - 60s\(^{-1}\)t]. The wave number is?
คำตอบ
(C)
1.0cm\(^{-1}\)
4
An object 40 cm high is 30cm from the pin hole camera. If the height of the image formed is 20 cm. What is the distance of the image from the pin height?
คำตอบ
(A)
15 cm
5
A bar magnet is placed near and lying along the axis of a solenoid connected to a galvanometer. The pointer of the galvanometer shows no deflection when?
คำตอบ
(B)
there is no relative motion
6
Tyres are treaded to?
คำตอบ
(B)
increase friction
7
A car starts from rest and covers a distance of 40 m in 10 s. Calculate the magnitude of its acceleration
คำตอบ
(C)
0.80 ms\(^{-2}\)
8
The relationship between the coefficient of linear expansion \(\alpha\) and volumetric expansion (\(\gamma\)) is-----------------
คำตอบ
(C)
3\(\alpha\)
9
Which of the following is not a consequence of hydrogen bubbles covering the copper plate of a primary cell?
คำตอบ
(C)
local action
10
A cell whose internal resistance is 0.55\(\Omega\) delivers a current of 4 A to an external resistor. The lost voltage of the cell is?
คำตอบ
(B)
2.20 V
11
Which of the following liquid is a poor conductor of electricity?
คำตอบ
(A)
Distilled water
12
An isotope has an initial activity of 120 Bq. 6 days later its activity is 15 Bq. The half-life is?
คำตอบ
(B)
2 days
13
The secondary pigments consist of?
คำตอบ
(C)
magenta, yellow, and cyan
14
A person standing waist-deep in a swimming pool appears to have short legs because of light?
คำตอบ
(B)
refraction
15
A tuning fork having a frequency of 312 Hz emits a wave which has a wavelength of 1.10 m. Calculate the velocity of sound
คำตอบ
(C)
343.2 ms\(^{-1}\)
16
When the plate area of a capacitor increases?
คำตอบ
(D)
the capacitance increases
17
A magnet relay is a device used for?
คำตอบ
(B)
controlling another circuit carrying larger current
18
According to kinetic molecular model in gases,
คำตอบ
(C)
the molecules are very far apart and occupy all the spaces made available to them
19
A current of 0.5 A flows through a resistor when connected to a 40 V battery. How much energy is dispatched in 2 minutes?
คำตอบ
(A)
2400 J
20
For a pear-shaped conductor shown above, the concentration of charge on the outside is highest at?
คำตอบ
(A)
X
21
The vapour pressure?
คำตอบ
(A)
increases non-linearly with measuring temperature
22
The potential energy in an elastic string of force constant k, which has an extension X is?
คำตอบ
(C)
½KX\(^{2}\)
23
A reservoir is filled with liquid of density 2000 kgm\(^{-1}\). Calculate the depth at which the pressure in the liquid will be equal to 9100 Nm\(^{-2}\) (g = 10 ms\(^{-2}\))
คำตอบ
(D)
0.455 m
24
Water is not a good thermometric liquid because it?
คำตอบ
(D)
wets glass
25
Which of these is a second-class lever?
คำตอบ
(D)
wheelbarrow
26
In the formation of sea breeze, wind blows from?
คำตอบ
(D)
sea to land
27
Which component of fiber-optic connector has a provision of entry for the fibre along with the fixation to connector housing?
คำตอบ
(A)
coupling device
28
In order to view the sun, the most suitable instrument to use is?
คำตอบ
(A)
helioscope
29
The eclipse of the moon occurs when?
คำตอบ
(C)
the earth comes exactly between the moon and the sun
30
The gravitational pull on the moon is \(\frac{1}{6}\) that of the earth. If a body weighs 6.0 N on the moon, what will be the weight on the earth?
คำตอบ
(D)
36.0 N
31
The amount of energy required to change a kilogram of ice block into water without a change in temperature is?
คำตอบ
(A)
specific latent heat of fusion of ice
32
Which expression gives magnetic flux?
คำตอบ
(C)
BA cos \(\theta\)
33
The graph of pressure (P) against the reciprocal of the volume (I/V) in Boyles's law is a?
คำตอบ
(D)
straight line
34
What quantity of heat is required to convert 20 g of ice at 0 ºC to water at the same temperature? (Specific latent heat of ice = 336 Jg\(^{-1}\))
คำตอบ
(C)
6.72 x 10\(^{3}\)J
35
A train of mass 1600 kg attains a speed of 25 ms\(^{-1}\) in 20 seconds. The power developed in the engine is?
