The cyclic octagon ABCDEFGH has
sides a, a, a, a, b, b, b, b respectively.
Find the radius of the circle that
circumscribes ABCDEFGH in terms
of a and b.
A block of mass M is placed on smooth
ground. Its upper surface is smooth and
vertical surface is rough with coefficient
of friction μ. A block of mass m_1 is placed
on its horizontal surface and tied with
a massless inextensible string passing
over smooth pulley. Its other end is
connected to another block of mass m_2 ,
which touches the vertical surface of
block M. Now a horizontal force F
starts acting on it.
Q1. Which of the following is incorrect
about above system?
(1) There exists a value of F at which
friction force is equal to zero
(2) When F = 0, the blocks cannot
remain stationary
(3) There exists two limiting values of
F at which the blocks m_1 and m_2 will
remain stationary w.r.t. block of mass
M
(4) The limiting friction between m_2
and M is independent of F
Q2. In the above case, let m_1 − μm_2 be
greater than 1. Choose the incorrect
value of F for which the blocks m_1 and
m_2 remain stationary with respect to
M
(1) (M + m_1 + m_2 )((m_2 g)/m_1 )
(2) ((m_2 (M + m_1 + m_2 ))/((m_1 − μm_2 )))g
(3) (((M + m_1 + m_2 )m_2 g)/((m_1 + μm_2 )))
(4) (M + m_1 + m_2 )(g/μ)
Q3. Let vertical part of block M be
smooth. Choose the correct alternative
(1) There exist two limiting values for
system to remain relatively at rest
(2) For one unique value of F, the blocks
m_1 and m_2 remain stationary with
respect to block M
(3) The blocks m_1 and m_2 cannot be in
equilibrium for any value of F
(4) There exists a range of mass M, for
which system remains stationary
A man of mass 85 kg stands on a lift of
mass 30 kg. When he pulls on the rope,
he exerts a force of 400 N on the floor of
the lift. Calculate acceleration of the
lift. Given g = 10 m/s^2 .
Which forces of attraction are responsible
for liquefaction of H_2 ?
(a) Coulombic forces
(b) Dipole forces
(c) Hydrogen bonding
(d) Van der Waal′s forces.
Let f(x) is a quadratic equation and
x^2 − 2x + 3 ≤ f(x) ≤ 2x^2 − 4x + 4
for every x ∈ R
If f(5) = 26, then f(7) is equal to ...
(A) 38 (D) 74
(B) 50 (E) 92
(C) 56
A 5-kg body is suspended from a spring-
balance, and an identical body is
balanced on a pan of a physical
balance. If both the balances are kept
in an elevator, then what would happen
in each case when the elevator is moving
with an upward acceleration?