Science (English Medium) कक्षा ११ - CBSE Question Bank Solutions

Shown are several curves (Figure). Explain with reason, which ones amongst them can be possible trajectories traced by a projectile (neglect air friction).

Six point masses of mass m each are at the vertices of a regular hexagon of side l. Calculate the force on any of the masses.

Modulus of rigidity of ideal liquids is ______.

Modulus of rigidity of ideal liquids is ______.

The maximum load a wire can withstand without breaking, when its length is reduced to half of its original length, will ______.

A spring is stretched by applying a load to its free end. The strain produced in the spring is ______.

A mild steel wire of length 2L and cross-sectional area A is stretched, well within elastic limit, horizontally between two pillars (Figure). A mass m is suspended from the mid point of the wire. Strain in the wire is ______.

A rectangular frame is to be suspended symmetrically by two strings of equal length on two supports (Figure). It can be done in one of the following three ways;

(a)
(b)
(c)

The tension in the strings will be ______.

Consider two cylindrical rods of identical dimensions, one of rubber and the other of steel. Both the rods are fixed rigidly at one end to the roof. A mass M is attached to each of the free ends at the centre of the rods.

A wire is suspended from the ceiling and stretched under the action of a weight F suspended from its other end. The force exerted by the ceiling on it is equal and opposite to the weight.

1. Tensile stress at any cross section A of the wire is F/A.
2. Tensile stress at any cross section is zero.
3. Tensile stress at any cross section A of the wire is 2F/A.
4. Tension at any cross section A of the wire is F.

A rod of length l and negligible mass is suspended at its two ends by two wires of steel (wire A) and aluminium (wire B) of equal lengths (Figure). The cross-sectional areas of wires A and B are 1.0 mm² and 2.0 mm², respectively.

(Y_Al = 70 × 10⁹ Nm⁻² and Y_steel = 200 × 10⁹ Nm^–2)

1. Mass m should be suspended close to wire A to have equal stresses in both the wires.
2. Mass m should be suspended close to B to have equal stresses in both the wires.
3. Mass m should be suspended at the middle of the wires to have equal stresses in both the wires.
4. Mass m should be suspended close to wire A to have equal strain in both wires.

Is stress a vector quantity?

Consider a long steel bar under a tensile stress due to forces F acting at the edges along the length of the bar (Figure). Consider a plane making an angle θ with the length. What are the tensile and shearing stresses on this plane

1. For what angle is the tensile stress a maximum?
2. For what angle is the shearing stress a maximum?

The graph between two temperature scales A and B is shown in figure. Between upper fixed point and lower fixed point there are 150 equal division on scale A and 100 on scale B. The relationship for conversion between the two scales is given by ______.

The graph between two temperature scales A and B is shown in figure. Between upper fixed point and lower fixed point there are 150 equal division on scale A and 100 on scale B. The relationship for conversion between the two scales is given by ______.

Calculate the temperature which has same numeral value on celsius and Fahrenheit scale.

Calculate the temperature which has same numeral value on celsius and Fahrenheit scale.

Which of the following diagrams (Figure) depicts ideal gas behaviour?

(a)	(b)
(c)	(d)

Calculate the number of atoms in 39.4 g gold. Molar mass of gold is 197g mole^–1.

A box of 1.00 m³ is filled with nitrogen at 1.50 atm at 300K. The box has a hole of an area 0.010 mm². How much time is required for the pressure to reduce by 0.10 atm, if the pressure outside is 1 atm.