A force is represented by
where = distance and = time. The dimensions of are:
- A
- B
- C
- D
Show answer
Correct option: D
30 questions · 30 with the official NTA answer
A force is represented by
where = distance and = time. The dimensions of are:
Correct option: D
The relation between time and distance is , where and are constants. The relation between acceleration and velocity is :
Correct option: A
A coin is placed on a disc. The coefficient of friction between the coin and the disc is . If the distance of the coin from the center of the disc is , the maximum angular velocity which can be given to the disc, so that the coin does not slip away, is :
Correct option: B
In the given arrangement of a doubly inclined plane two blocks of masses and are placed. The blocks are connected by a light string passing over an ideal pulley as shown. The coefficient of friction between the surface of the plane and the blocks is 0.25. The value of , for which kg will move down with an acceleration of , is: (take and )
double inclined plane with block M on the 53° incline and block m on the 37° incline, connected by a string over a pulley at the apex
4.5 kg
9 kg
2.25 kg
6.5 kg
Correct option: A
An artillery piece of mass fires a shell of mass horizontally. Instantaneously after the firing, the ratio of kinetic energy of the artillery and that of the shell is:
Correct option: B
Four identical particles of mass are kept at the four corners of a square. If the gravitational force exerted on one of the masses by the other masses is , the length of the sides of the square is
Correct option: B
A small steel ball is dropped into a long cylinder containing glycerine. Which one of the following is the correct representation of the velocity time graph for the transit of the ball?
v–t graph, straight line rising linearly from origin
v–t graph, velocity rises linearly then falls linearly to zero (triangular shape)
v–t graph, velocity rises steeply then saturates to a constant terminal value
v–t graph, velocity constant initially then decreases linearly
Correct option: C
The given figure represents two isobaric processes for the same mass of an ideal gas, then
V–T graph with two straight lines from origin O, line steeper (above) line
Correct option: A
The parameter that remains the same for molecules of all gases at a given temperature is :
mass
speed
momentum
kinetic energy
Correct option: D
Two charges and are separated by a distance in air. At a distance from charge , the resultant electric field is zero. The value of is :
Correct option: C
Two conductors have the same resistances at but their temperature coefficients of resistance are and . The respective temperature coefficients for their series and parallel combinations are :
Correct option: A
A rigid wire consists of a semicircular portion of radius and two straight sections. The wire is partially immerged in a perpendicular magnetic field as shown in figure. The magnetic force on the wire if it has a current is:
U-shaped wire with semicircular top of radius R inside a region of magnetic field pointing out of the page (dots), with x–y axes shown; the two straight sections extend downward out of the field region
Correct option: B
A coil is places perpendicular to a magnetic field of 5000 T. When the field is changed to 3000 T in 2 s, an induced emf of 22 V is produced in the coil. If the diameter of the coil is 0.02 m, then the number of turns in the coil is:
7
140
35
70
Correct option: D
In a plane EM wave, the electric field oscillates sinusoidally at a frequency of Hz and an amplitude of . The total average energy density of the electromagnetic field of the wave is : [Use ]
Correct option: A
The refractive index of a prism with apex angle is . The angle of minimum deviation is :
Correct option: A
When a metal surface is illuminated by light of wavelength , the stopping potential is 8V. When the same surface is illuminated by light of wavelength , stopping potential is 2V. The threshold wavelength for this surface is:
Correct option: D
If the wavelength of the first member of Lyman series of hydrogen is . The wavelength of the second member will be
Correct option: A
Identify the logic operation performed by the given circuit.
logic circuit — inputs A and B each pass through a NOT gate (inverter), whose outputs feed a NAND gate giving output Y
AND
OR
NAND
NOR
Correct option: B
The fundamental frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe. If length of the open pipe is 60 cm, the length of the closed pipe will be:
60 cm
45 cm
30 cm
15 cm
Correct option: D
If the percentage errors in measuring the length and the diameter of a wire are 0.1% each. The percentage error in measuring its resistance will be:
0.1%
0.2%
0.3%
0.144%
Correct option: C
A body starts falling freely from height hits an inclined plane in its path at height . As a result of this perfectly elastic impact, the direction of the velocity of the body becomes horizontal. The value of for which the body will take the maximum time to reach the ground is ________.
Answer: 2
A solid circular disc of mass 50 kg rolls along a horizontal floor so that its center of mass has a speed of 0.4 m/s. The absolute value of work done on the disc to stop it is __________ J.
Answer: 6
The depth below the surface of sea to which a rubber ball be taken so as to decrease its volume by 0.02% is _______ .
(Take density of sea water , Bulk modulus of rubber , and )
Answer: 18
A particle performs simple harmonic motion with amplitude . Its speed is increased to three times at an instant when its displacement is . The new amplitude of motion is . The value of is ________.
Answer: 7
A parallel plate capacitor with plate separation 5 mm is charged up by a battery. It is found that on introducing a dielectric sheet of thickness 2 mm , while keeping the battery connections intact, the capacitor draws 25% more charge from the battery than before. The dielectric constant of the sheet is ________.
Answer: 2
Equivalent resistance of the following network is ________ .
resistor network between terminals A and B — three parallel branches ( 6 shown with , 2 , and 3 with 3 ) linked by series resistors of 2 ( top-left) and 2 ( top-right)
Answer: 1
An electron moves through a uniform magnetic field . At a particular instant of time, the velocity of electron is . If the magnetic force acting on electron is , where is the charge of electron, then the value of is ________ .
Answer: 5
A small square loop of wire of side is placed inside a large square loop of wire of side . The loops are coplanar and their centers coincide. The value of the mutual inductance of the system is , where ______.
Answer: 128
Two waves of intensity ratio 1:9 cross each other at a point. The resultant intensities at that point, when (a) Waves are incoherent is (b) Waves are coherent is and differ in phase by . If then ______.
Answer: 13
The mass defect in a particular reaction is 0.4g. The amount of energy liberated is kWh, where ______.
(speed of light m/s)
Answer: 1