List of practice Questions

A concave lens of focal length 20 cm produces an image half the size of the real object. The distance of the real object is

A monochromatic source of wavelength $60\, nm$ was used in Young?s double slit experiment to produce interference pattern. $I_1$ is the intensity of light at a point on the screen where the path difference is $150\, nm.$ The intensity of light at a point where the path difference is $200\, nm$ is given by

A particle of mass $m$ and charge $q$ is placed at rest in uniform electric field $E$ and then released. The kinetic energy attained by the particle after moving a distance $y$ is

From a circular ring of mass $M$ and radius $R$, an arc corresponding to a $ {{90}^{o}} $ sector is removed. The moment of inertia of the remaining part of the ring about an axis passing through the centre of the ring and perpendicular to the plane of the ring is $k$ times $ M{{R}^{2}} $ . Then the value of $k$ is

A body is thrown up with a speed $u$, at an angle of projection $\theta$. If the speed of the projectile becomes $\frac{u}{\sqrt{2}}$ on reaching the maximum height, then the maximum vertical height attained by the projectile is

A force F is applied on a square plate of side L. If percentage error in determination of L is 2% and that in F is 4%, permissible error in pressure is

A liquid is filled upto a height of $20\, cm$ in a cylindrical vessel. The speed of liquid coming out of a small hole at the bottom of the vessel is $(g = 10 \; ms^{-2})$

An engine of power $58.8\, kW$ pulls a train of mass $2 \times 10^{5}\, kg$ with a velocity of $36\, kmh ^{-1}$. The coefficient of friction is

If 10% of a radioactive material decays in 10 days the percentage of the material that decays in 20 days is

Ekta earns 3000 Rs. in 10 days. How much will she earn in 30 days?

\(∫\frac{dx}{e^x+e^{-x}}\) is equal to

A plane electromagnetic wave travelling along the $ X- $ direction has a wavelength of $ 3 \,mm $ . The variation in the electric field occurs in the $ Y- $ direction with an amplitude $ 66\,V{{m}^{-1}} $ . The equations for the electric and magnetic fields as a function of $ x $ and $t$ are respectively.

A ball dropped from a height of $2\,m$ rebounds to a height of $1.5\,m$ after hitting the ground. Then the percentage of energy lost is

Do you think the feeling of depression Johnsy has is common among teenagers?

Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of the laws of reflection?

Are the following statements true?
(a) 40 persons: 200 persons = ₹15: ₹75
(b) 7.5 litres : 15 litres = 5 kg: 10 kg
(c) 99 kg: 45 kg = ₹ 44: ₹20
(d) 32 m: 64 m = 6 sec: 12 sec
(e) 45 km: 60 km = 12 hours: 15 hours

Anish made 42 runs in 6 overs and Anup made 63 runs in 7 overs. Who made more runs per over?

An object of mass, m is moving with a constant velocity, v. How much work should be done on the object in order to bring the object to rest?

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –

An edge of a variable cube is increasing at the rate of \(3 cm/s\). How fast is the volume of the cube increasing when the edge is \(10 cm\) long?

Differentiate between metal and non-metal on the basis of their chemical properties.

A Cassegrain telescope uses two mirrors as shown in Fig. 9.26. Such a telescope is built with the mirrors 20 mm apart. If the radius of curvature of the large mirror is 220 mm and the small mirror is 140 mm, where will the final image of an object at infinity be?

Although the details of the structure of monoclinic sulphur are not well known it probably consists of

A man of mass $60 \,kg$ climbed down using an elevator. The elevator had an acceleration $4 \, ms^{-2}$. If the acceleration due to gravity is $10 \, ms^{-2}$, the main apparent weight on his way down is

A solid sphere and a hollow sphere, both of the same size and same mass roll down an inclined plane .Then