240v
340v
480v
57600v
Correct answer is B
The relationship between the peak value and r.m.s value of electricity supply is given as
V\(_{r.m.s}\) = \(\frac{V_o}{\sqrt{2}}\)
where Vo = peak voltage
∴ Vo = V\(_{r.m.s}\) × √2
= 240 × √2
= 339.5v
= 340v
1:4
4:1
1:1
2:1
Correct answer is C
H = mcθ
HP = HQ, θP = 2θ,
mP = \(\frac{1}{2}\)mQ
∴ HP = mQCPθP, also HQ = mQCQθQ
Since HP = HQ
∴ mPcPθP = mQcPθq
Putting in the conditions
\(\frac{1}{2}\)mQ × cP × 2θQ = mQ × θQ × cQ
∴ cP = cQ
\(\frac{C_p}{C_Q}\)= \(\frac{1}{1}\)
= 1:1
10 cm
16 cm
5 cm
14 cm
Correct answer is D
Magnification = \(\frac{\text{Length of camera}}{\text{distance of object from pin hole}}\)
m = \(\frac{12}{60}\)
= 0.2
Also magnification m = \(\frac{\text{Height of image}}{\text{Height of object}}\)
∴ Height of image = m × height of object
= 0.2 × 70
= 14cm
The S.I unit of moment of a force is
kgm
Nm
Jm
µm\(^{-1}\)
Correct answer is B
Moment of a force is the product of a force and the perpendicular distance from the line of action of the force
Moment = force × distance
= N × m
= Nm
An element and its isotope only differ in the number of
protons
electrons
ions
neutrons
Correct answer is D
Isotopy is due to difference in mass number, what causes the difference is the difference in the number of neutrons present