NEET Questions

📑 Chapter:Units And Measurement

🎯Topic:Percentage Error

🔄Ncert Concepts :Percentage Error, Area, Rectangle

42.

A physical quantity $P$ is related to four observables $a$ , $b$ , $c$ , and $d$ as follows: $P = a^3b^2/\sqrt{c}d$ . The percentage errors of measurement in $a$ , $b$ , $c$ , and $d$ are 1%, 3%, 4%, and 2%, respectively. What is the percentage error in the quantity $P$ ?

13%

15%

Question Tags

📑 Chapter:Units And Measurement

🎯Topic:Percentage Error

🔄Ncert Concepts :Percentage Error, Error Propagation

43.

A lens has a focal length 'f'. Derive the lens maker's formula, relating f to the refractive index 'n' of the lens material and the radii of curvature $R_1$ and $R_2$ of its surfaces.

$\frac{1}{f} = \frac{1}{R_1} + \frac{1}{R_2}$

$\frac{1}{f} = (n-1)(\frac{1}{R_1} + \frac{1}{R_2})$

$\frac{1}{f} = (n-1)(\frac{1}{R_1} - \frac{1}{R_2})$

$f = (n-1)(\frac{1}{R_1} - \frac{1}{R_2})$

Question Tags

📑 Chapter:Units And Measurement

🎯Topic:Deriving Equations

🎯Difficulty :Medium

🔄Ncert Concepts :Ray Optics, Lens Maker's Formula

44.

A man of mass $m$ is standing on a weighing machine placed in a lift. Initially, the lift is stationary. The lift then begins to ascend with an acceleration of $g/3$ , then moves with a uniform velocity, and finally decelerates at a rate of $g/4$ before coming to rest. If the readings of the weighing machine during the ascent, uniform motion, and descent are $W_1$ , $W_2$ , and $W_3$ respectively, which of the following relations is correct?

$W_1 > W_2 > W_3$

$W_1 < W_2 < W_3$

$W_1 = W_2 = W_3$

$W_1 > W_2 = W_3$

Question Tags

🎯Topic:Connected Bodies And Apparent Weight

🔄Ncert Concepts :Apparent Weight, Connected Bodies, Newton's Laws of Motion

45.

A rocket in space ejects gas at a constant rate $\mu$ kg/s with a constant speed $v_e$ relative to the rocket. If the initial mass of the rocket is $M_0$ , what is its velocity after time $t$ ?

$\mu v_e t$

$v_e \frac{\mu t}{M_0}$

$v_e\ln(\frac{M_0}{M_0 - \mu t})$

$v_e\ln(\frac{M_0 - \mu t}{M_0})$

Question Tags

🔄Ncert Concepts :Law of Conservation of Linear Momentum, Variable Mass System, Rocket Propulsion

46.

Two identical balls of clay, each with mass $m$ and speed $v$ , collide head-on and stick together. What is the magnitude of the impulse experienced by each ball?

$0$

$mv$

$2mv$

$mv/2$

Question Tags

🔄Ncert Concepts :Law of Conservation of Linear Momentum, Impulse, Inelastic Collision

47.

A ball of mass $m$ moving with velocity $v$ strikes a wall at an angle $heta$ and rebounds with the same speed at the same angle. If the collision time is $\Delta t$ , what is the average force exerted by the wall on the ball?

$\frac{mv\cosheta}{\Delta t}$

$\frac{2mv\cosheta}{\Delta t}$

$\frac{2mv\sinheta}{\Delta t}$

$\frac{mv\sinheta}{\Delta t}$

Question Tags

🔄Ncert Concepts :Law of Conservation of Linear Momentum, Impulse, Collision

48.

A man of mass $M$ standing on a frictionless surface throws a ball of mass $m$ with a velocity $v$ at an angle $heta$ with the horizontal. The velocity of the man after he throws the ball is:

$\frac{mv}{M}$

$-\frac{mv\cosheta}{M}$ in the horizontal direction

$-\frac{mv\sinheta}{M}$ in the vertical direction

Zero

Question Tags