Science (English Medium) Class 11 - CBSE Question Bank Solutions for Physics

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.

The displacement of a particle is represented by the equation `y = 3 cos (pi/4 - 2ωt)`. The motion of the particle is ______.

The displacement of a particle is represented by the equation y = sin³ωt. The motion is ______.

The displacement of a particle varies with time according to the relation y = a sin ωt + b cos ωt.

Motion of a ball bearing inside a smooth curved bowl, when released from a point slightly above the lower point is ______.

1. simple harmonic motion.
2. non-periodic motion.
3. periodic motion.
4. periodic but not S.H.M.

Displacement vs. time curve for a particle executing S.H.M. is shown in figure. Choose the correct statements.

1. Phase of the oscillator is same at t = 0 s and t = 2s.
2. Phase of the oscillator is same at t = 2 s and t = 6s.
3. Phase of the oscillator is same at t = 1 s and t = 7s.
4. Phase of the oscillator is same at t = 1 s and t = 5s.

What is the ratio of maxmimum acceleration to the maximum velocity of a simple harmonic oscillator?

The earth has a radius of 6400 km. The inner core of 1000 km radius is solid. Outside it, there is a region from 1000 km to a radius of 3500 km which is in molten state. Then again from 3500 km to 6400 km the earth is solid. Only longitudinal (P) waves can travel inside a liquid. Assume that the P wave has a speed of 8 km s^–1 in solid parts and of 5 km s^–1 in liquid parts of the earth. An earthquake occurs at some place close to the surface of the earth. Calculate the time after which it will be recorded in a seismometer at a diametrically opposite point on the earth if wave travels along diameter?

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the amplitude.

In the given progressive wave y = 5 sin (100 πt – 0.4 πx) where y and x are in m, t is in s. What is the wavelength.