The unit of moment of a couple can be expressed in?
N m-1
N m-2
N m
N m2
Correct answer is C
The unit of a couple is Newton-meter (N M)
37.50 cm
75.00 cm
18.75
25.00 cm
Correct answer is A
The least distance of distinct vision required = 25 cm.
∴ for the person to see an object clearly at 25 cm from the eye, the image must be formed at 75 cm on the same side of lens, at his near point.
∴ U = 25 cm; V = -75 cm (image should be virtual)
thus (1)/f = (1)/v +(1)/u
= (1)/75 + (1)/25
=(-1 + 3)/75 = (2)/75
∴f = (75)/2 = 37.50
The wavelength of the first overtone of a note in a closed pipe of length 33 cm is?
33 cm
44 cm
22 cm
17 cm
Correct answer is B
In a closed tube, the fundamental note occurs when the length of the tube l = (λ)/4,
the first over tone occurs when the length of the tube l = (3)/4λ.
λ = (4)/3 l = (4)/3 x (33)/T = 44 cm
Non-luminous object can be seen because they
reflect light
are near
are polished
emit light
Correct answer is A
No explanation has been provided for this answer.
45 m
80 m
15 m
60 m
Correct answer is C
Refraction index (n)= (Real depth)/App. depth
For 80 m Real depth: (4)/3 = (80)/App. depth
App. dept = (80 x 3)/4 = 60 m
For 60 m real depth; (4)/3 = (60)/ App. depth
App. depth = (60 x 3)/4 = 45 m
∴change in App. depth = 60 -45 = 15 m