For Bragg’s diffraction by a crystal to occur, then the X-ray of wavelength and interatomic distance d must be

1. λ is greater than 2d

2. λ equals 2d

3. λ is smaller than or equal to 2d

4. λ is smaller than 2d

Subtopic:  X-Ray (OLD NCERT) |
 57%
Please attempt this question first.
Hints

A wire having mass m and length l can freely slide on a pair of parallel smooth horizontal rails placed in vertical magnetic field B. The rails are connected by a capacitor of capacitance C. The electric resistance of the rails and the wire as shown in the figure. Then, the acceleration of the wire can be given as 

1. a=C2B2 l-Fm

2. a=Fm+CBl

3. a=FC2B2 lm

4. a=Fm+C2B2l

Subtopic:  Motional emf |
Please attempt this question first.
Hints

advertisementadvertisement

Consider the situation shown in figure A spring of spring constant 400 N/m is attached at one end to a wedge fixed rigidly with the horizontal part. A 40 g mass is released form rest while situated at a height 5 cm the curved track. The minimum deformation in the spring is nearly equal to  

1. 9.8 m

2. 9.8 cm

3. 0.98 m

4. 0.009 km

Subtopic:  Work Done by Variable Force |
 57%
Please attempt this question first.
Hints

A block having mass m collides with an another stationary block having mass 2 m. The lighter block comes to rest after collision. If the velocity of first block is v, then the value of coefficient of restitution will must be

1. 0.5

2. 0.4

3. 0.6

4. 0.8

Subtopic:  Linear Momentum |
 56%
Please attempt this question first.
Hints

A uniform sphere of mass 500 g rolls without slipping on a plane surface so that its centre moves at a speed of 0.02 m/s. 
The total kinetic energy of rolling sphere would be (in J)

1. 1.4×10-4 J

2. 0.75×10-3 J

3. 5.75×10-3 J

4. 4.9×10-5 J

Subtopic:  Rolling Motion (OLD NCERT) |
 56%
Please attempt this question first.
Hints

advertisementadvertisement

The force on a particle as the function of displacement x(in x-direction) is given by 
F = 10 + 0.5 x 
The work done corresponding to displacement of particle from x = 0 to x = 2 unit is

1. 25 J

2. 29 J

3. 21 J

4. 18 J

Subtopic:  Work Done by Variable Force |
 67%
Please attempt this question first.
Hints
Please attempt this question first.

The reading of a spring balance corresponds to 100 N while situated at the north pole and a body is kept on it. The weight record on the same scale if it is shifted to the equator, is 

1. 99.66 N

2. 110 N

3. 97.66 N

4. 106 N

Subtopic:  Acceleration due to Gravity |
 51%
Please attempt this question first.
Hints

If the intensity is increased by a factor of 20; then how many decibels in the sound level increased?

1. 18

2. 13

3. 9

4. 7

Subtopic:  Pressure Wave in Sound |
 63%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints

advertisementadvertisement

On the same path, the source and observer are moving such a ways that the distance between these two increases with the time. The speeds of source and observer are same and equal to  with respect to the ground while no wind is blowing. The apparent frequency received by observer is 1950 Hz then the original frequency must be (the speed of sound in present medium is 340 m/s)

1. 2068 Hz

2. 2100 Hz

3. 1903 Hz

4. 602 Hz

Subtopic:  Doppler's Effect (OLD NCERT) |
 52%
Please attempt this question first.
Hints