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With what minimum acceleration can a fireman slide down a rope while the breaking strength of the rope is $\frac{2}{3}$ of his weight?
Calculate the maximum acceleration of a moving car so that a body lying on the floor of the car remains stationary. The coefficient of static friction between the body and the floor is $0.15$. (take $g=10 \text{ m s}^{-2}$)
Consider a simple circuit shown in the figure. R' stands for variable resistance. R' can vary from R₀ to infinity. r is the internal resistance of the battery (r<<R<<R₀). (a) Potential drop across AB is nearly constant as R' is varied. (b) Current through R' is nearly constant as R' is varied. (c) Current I depends sensitively on R'. (d) I ≥ V/(r+R) always. Which among the following statements is correct?
A man is standing on a spring platform. Reading of spring balance is 60 kg-wt. If the man jumps off the platform, then the reading of the spring balance:
A mass is supported on a frictionless horizontal surface. It is attached to a string and rotates about a fixed centre at an angular velocity $\omega_0$. If the length of the string and angular velocity are doubled, the tension in the string which was initially $T_0$ is now:
According to the kinetic theory of gases, at absolute zero temperature:
In the above diagram, the acceleration of the car will be:
When a torque acting upon a system is zero, then which of the following will be constant?
A ball of mass 0.25 kg attached to the end of a string of length 1.96 m is moving in a horizontal circle. The string will break if the tension is more than 25 N. What is the maximum speed with which the ball can be moved?
A bob is whirled in a horizontal plane by means of a string with an initial speed of $\omega$ rpm. The tension in the string is $T$. If speed becomes $2\omega$ while keeping the same radius, the tension in the string becomes:
A motor cyclist moving with a velocity of $72 \text{ km/hour}$ on a flat road takes a turn on the road at a point where the radius of curvature of the road is $20 \text{ meters}$. The acceleration due to gravity is $10 \text{ m/sec}^2$. In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than:
A solar cell is a:
Two coils of self-inductance $2 \text{ mH}$ and $8 \text{ mH}$ are placed so close together that the effective flux in one coil is completely linked with the other. The mutual inductance between these coils is:
A 1 kg stone at the end of 1 m long string is whirled in a vertical circle at a constant speed of 4 m/s. The tension in the string is 6 N, when the stone is at (Take g = 10 m/s²):
When a body of mass $m$ just begins to slide as shown, match List-I with List-II: **List-I** (a) Normal reaction (b) Frictional force ($f_s$) (c) Weight ($mg$) (d) $mg \sin \theta$ **List-II** (i) $P$ (ii) $Q$ (iii) $R$ (iv) $S$
The electric field at a distance 3R/2 from the centre of a charged conducting spherical shell of radius R is E. The electric field at a distance R/2 from the centre of the sphere is
A cylinder of radius R and length L is placed in a uniform electric field E parallel to the cylinder axis. The total flux for the surface of the cylinder is given by
A uniform rope of length $l$ lies on a table. If the coefficient of friction is $\mu$, then the maximum length $l_1$ of the part of this rope which can overhang from the edge of the table without sliding down is:
A ball of mass 0.1 kg is whirled in a horizontal circle of radius 1 m by means of a string at an initial speed of 10 rpm. Keeping the radius constant, the tension in the string is reduced to one quarter of its initial value. The new speed is:
A $1 \text{ kg}$ object strikes a wall with velocity $1 \text{ ms}^{-1}$ at an angle of $60^\circ$ with the wall and reflects at the same angle. If it remains in contact with the wall for $0.1 \text{ s}$, then the force exerted on the wall is: