Mix Test - 6...

What is the equivalent resistance across A and B?

A block of mass 2 kg is placed on the surface of a trolley of mass 20 kg, which is on a smooth surface. The coefficient of friction between the block and the surface of the trolley is 0.25. If a horizontal force of 2 N acts on the block, then the acceleration of the system (in ms^-2) is (Take g = 10 ms^-2)

The escape velocity from the Earth is v_e. What is the escape velocity from a planet whose radius is twice that of the Earth and mean density is the same as that of the Earth?

Two wires with the same dimensions and resistivities ₁ and ₂ are connected in series. The equivalent resistivity of the combination is

A receiving station on the ground is receiving a signal of frequency 5 MHz from a transmitter at a height of 300 m above the surface of Earth (radius = 6.4 10⁶ m) at a distance of 100 km from the receiver. The signal is coming via

Two bullets A and B are fired from a gun with the same speed, but at angles 30^o and 60^o to the horizontal, respectively. Which of the following statements is correct?

The SI unit of the universal gas constant R is

Two glasses have dispersive powers in the ratio 2 : 3. These glasses are used in the manufacturing of an achromatic objective of focal length 20 cm. What are the respective focal lengths of the two lenses of the objective?

In an AC circuit, the potential differences across an inductance and a resistance connected in series are 16 V and 20 V, respectively. The total potential difference across the circuit is

In Young's double slit experiment, the two slits act as coherent sources of equal amplitude A and of wavelength . In another experiment with the same set up, the two slits are sources of equal amplitude A and wavelength ^_, but are incoherent. The ratio of the intensity of light at the midpoint of the screen in the first case to that in the second case is

A person measures the time period of a simple pendulum inside a stationary lift and finds it to be T. If the lift starts accelerating upwards with an acceleration of g/3, then the time period of the pendulum will be

2 cylindrical rods of lengths l₁ and I₂ and radii r₁ and r₂ have thermal conductivities k₁ and k₂, respectively. The ends of the rods are maintained at the same temperature difference. If l₁ = 2I₂ and r₁ = r₂/2, then the rate of heat flow in them will be the same, if k₁/k₂ is equal to

A radio transmitter operates on a wavelength of 1500 m at a power of 400 kilowatt. The energy of the radio photon (in joules) is

A uniform rod of length L is suspended from one end such that it is free to rotate about an axis passing through that end and perpendicular to the length. What minimum speed must be imparted to the lower end, so that the rod completes one full revolution?

A charge having magnitude Q is divided into parts q and (Q – q), which are held at a certain distance r apart. The force of repulsion between the two parts will be maximum, if the ratio q/Q is