Find the dimensions of A × (B + C)D where A is mass, dimensions of B is unknown, C is energy and D is dimensionless constant:
a. M2L2T−1 b. M2L2T−2 c. M2L1T−2 d. M1L2T−2 Solution: Answer: (b) Dimension of A × (B + C)D equal to... View Article
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Given statements are based on Bohr’s atomic model for hydrogen-like atoms
Statement-1. As the principal quantum number increases, the speed of the electron also increases. Statement-2. Speed of electron increases as... View Article
A sound source and a detector are moving away from each other with an equal speed of 20 m/s. The detector heard a sound of frequency 1800 Hz from the source. What is the original frequency released by the source? Assume speed of sound = 340 m/s.
a. 2200 HZ b. 1800 HZ c. 2025 HZ d. 1500 HZ Solution: Answer: (c) fapp = 1800 Hz =... View Article
Chain of length 1 m is hanging as shown in the figure. The mass of the chain is 3 kg
Question: Chain of length 1 m is hanging as shown in the figure. The mass of the chain is 3... View Article
For a hydrogen-like atom, the frequency of transition from n = 3 to n = 1 is 192 × 1015 Hz, then find the frequency of transition from n = 2 to n = 1
a. 162 x 1015 Hz b. 226 x 1015 Hz c. 162 x 1018 Hz d. None Solution: Answer: (a)
Find the capacitance in a series LCR circuit in order to get maximum power. (XL = 250 Ω and f = 50 Hz).
a. 10.7 μF b. 12.7 μF c. 14.7 μF d. 14.9 μF Solution: Answer: (b) As we know that, for... View Article
In YDSE, d is the distance between slits and D is the distance between screen and slit plane. If y1 is the distance of 1st maxima from the central maxima for red light and y2 is the distance for violet light then what is the difference between the wavelength of red and violet?
a. \(\begin{array}{l}\frac{(y_{1}+y_{2})d}{D}\end{array} \) b. \(\begin{array}{l}\frac{(y_{1}-y_{2})d}{D}\end{array} \) c. \(\begin{array}{l}\frac{(y_{1}-y_{2})D}{d}\end{array} \) d. \(\begin{array}{l}\frac{(y_{1}+y_{2})D}{d}\end{array} \) Solution: Answer: (b) From the condition of maximum... View Article
There is a soap bubble of radius 6 cm and it has another soap bubble of radius 3 cm inside it. Find the equivalent radius of the soap bubble which has the same excess pressure, as the pressure inside the bubble of radius 3 cm.
a. 2 cm b. 1 cm c. 9 cm d. 3 cm Solution: Answer: (a) We have from the given... View Article
Find the difference in heights in limbs as shown in the given data. Surface tension T =7.3 × 10−2 N/m, the density of water ρ = 1000 Kg/m3 and the angle of contact θ = 0°.
a. 1.19 m b. 2.19 m c. 3.19 m d. 4.19 m Solution: Answer: (b)
The backside of a truck is open and a box of 40 kg is placed 5 m away from the rear end. The coefficient of friction of the box with the surface of the truck is 0.15. The truck starts from rest with 2 m/s2 acceleration. Calculate the distance covered by the truck when the box falls off
1) 20 m 2) 30 m 3) 40 m 4) 50 m Answer: 1) 20 m Solution: Given, Mass of the... View Article
Two masses 8 kg and 12 kg are connected at the two ends of a string that goes over a frictionless pulley. Calculate the acceleration of the masses and the tension in the string. (take, g =10 m/s2)
1) 8 m/s2 , 144 N 2) 4 m/s2 , 112 N 3) 6 m/s2 , 128 N 4) 2... View Article
An object is gently placed on a long conveyor belt moving with 11 ms-1. If the coefficient of friction is 0.4, then the block will slide in the belt up to a distance of
1) 10.21 m 2) 15.125 m 3) 20.3 m 4) 25.6 m Answer: Given, u = 11m/s Coefficient of friction... View Article
A mass M kg is suspended by a weightless string. The horizontal force required to hold the mass at 60° with the vertical is
1) Mg 2) Mg√3 3) Mg(√3 +1) 4) Mg/√3 Answer: 2) Mg√3 Solution: The tension acting on the string at equilibrium is... View Article
A block of mass 2 kg rests on a horizontal surface. If a horizontal force of 5 N is applied on the block, the frictional force on it is ( take, µk = 0.4, µs = 0.5 )
1) 5 N 2) 10 N 3) 8 N 4) zero Answer: 3) 8 N Solution: F = μkmg = 0.4 x... View Article
A uniform metal chain is placed on a rough table such that one end of it hangs down over the edge of the table. When one-third of its length hangs over the edge, the chain starts sliding. Then, the coefficient of static friction is
1) 3/4 2) 1/4 3) 2/3 4) 1/3 5) 1/2 Answer: 5) 1/2 Solution: Coefficient of friction, μ= F/R = \(\begin{array}{l}\mu = \frac{F}{R}=\left... View Article
The engine of a car produces an acceleration of 6ms-2 in the car. If this car pulls another car of the same mass, then the acceleration would be
1) 6 ms-2 2) 12 ms-2 3) 3 ms-2 4) 1.5 ms-2 Answer: 3) 3 ms-2 Solution: Let the mass of... View Article
A steel wire can withstand a load up to 2940 N. A load of 150 kg is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position so that the wire does not break when the load passes through the position of equilibrium is
1) 30° 2) 60° 3) 80° 4) 85° Answer: 2) 60° Solution: T cos θ = mg ⇒ cos θ = mg/T... View Article
A shell initially at rest explodes into two pieces of equal mass, the two pieces will
1) move with different velocities in different directions 2) move with the same velocity in opposite directions 3) move with... View Article
A rocket of mass 1000 kg is exhaust gases at a rate of 4 kgs-1 with a velocity of 3000 ms-1. The thrust developed on the rocket is
1) 12000 N 2) 120 N 3) 800 N 4) 200 N Answer: 1) 12000 N Solution: F = V (dm/dt)... View Article
Three guns are aimed at the centre of a circle. They are mounted on the circle, 120° apart. The fire in a timed sequence, such that the three bullets collide at the centre and mash into a stationary lump. Two of the bullets have identical masses of 4.5 g each and speeds of v1 and v2. The third bullet has a mass of 2.50 g and a speed of 575 ms-1. Find the unknown speeds.
1) 200 ms-1 each 2) 145 ms-1 and 256 ms-1 3) 536 ms-1 and 320 ms-1 4) None of the... View Article
