# A charged particle is accelerated by a potential of 200 V. If its velocity is 8.4 × 108 m/s, then the value of e/m for that particle is: 1. 17.6 × 1016 2. 14.5 × 1012 3. 1.76 × 1015 4. 1.45 × 1015

Subtopic:  Electric Field |
61%
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When an open organ is dipped in water up to half of its height, then its frequency will become:
1. half
2. double
3. remain same
4. four times

Subtopic:  Standing Waves |
58%
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A sound source producing waves of frequency 300 Hz and wavelength 1 m observer is stationary, while the source is going away with the velocity 30 m/s, then apparent frequency heard by the observer is:

1. 270 Hz

2. 273 Hz

3. 383 Hz

4. 300 Hz

Subtopic:  Doppler's Effect (OLD NCERT) |
67%
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A particle moves towards east for 2 s with velocity 15 m/s and move towards north for 8 s with velocity 5 m/s. Then, the average velocity of the particle is:

1. 2 m/s

2. 5 m/s

3. 7 m/s

4. 10 m/s

Subtopic:  Average Speed & Average Velocity |
60%
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Relation between a wavelength of photon and electron of same energy is:
1. $$\lambda_{p h}>\lambda_e$$
2. $$\lambda_{p h}<\lambda_e$$
3. $$\lambda_{p h}=\lambda_e$$
4. $$\frac{\lambda_e}{\lambda_{p h}}=\text { constant }$$

Subtopic:  De-broglie Wavelength |
52%
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Match the following.

 A. Angular momentum 1 [M-1L2T-2] B. Torque 2 [M1T-2] C. Gravitational constant 3 [M1L2T-2] D. Tension 4 [M1L2T-1]

1. C-2, D-1
2. A-4, B-3
3. A-3, C-2
4. B-2, A-1

Subtopic:  Dimensions |
72%
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If we increase the kinetic energy of a body by 300%, then percent increase in its momentum is:

1. 50%

2. 300%

3. 100%

4. 150%

Subtopic:  Concept of Work |
56%
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Change in acceleration due to gravity is same at height h above the Earth surface and  depth $$x ,$$ then relation between $$x$$ and $$h$$ is: ($$h$$ and $$x<<R_e$$)

1. $$x=h$$
2. $$x=2h$$
3. $$x=\frac h2$$
4. $$x=h^2$$

Subtopic:  Acceleration due to Gravity |
77%
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A mass of $$1~\mathrm{kg}$$ is suspended from a spring of force constant $$400$$ N, executing SHM total energy of the body is $$2$$ J, then the maximum acceleration of the spring will be:
1. $$4 \mathrm{~m} / \mathrm{s}^2$$
2. $$40 \mathrm{~m} / \mathrm{s}^2$$
3. $$200 \mathrm{~m} / \mathrm{s}^2$$
4. $$400 \mathrm{~m} / \mathrm{s}^2$$

Subtopic:  Energy of SHM |
64%
Two capacitors of capacities $$C_1$$ and $$C_2$$ are charged upto the potential $$V_1$$ and $$V_2,$$ then the condition for not flowing the charge between them when connected the capacitors, in parallel is:
1. $$C_1=C_2$$
2. $$C_1V_1=C_2V_2$$
3. $$V_1V_2$$
4. $$\frac{C_1}{V_1}=\frac{C_2}{V_2}$$