1. A
   Temperature decreases with height in the stratosphere.
2. B
   Temperature is constant at different heights in the stratosphere.
3. C
   Temperature increases with height in the troposphere at an average rate of 6·5 °C per kilometre.
4. D
   Temperature decreases with height in the troposphere at an average rate of 6·4 °C per kilometre.

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1. A
   Thermocline
2. B
   Halocline
3. C
   Photic zone
4. D
   Pycnocline

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1. A
   Treatment with washing soda
2. B
   Calgon's method
3. C
   Boiling
4. D
   Ion exchange method

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1. A
   $3\text{Cu} + 8\text{HNO}_3\text{ (dilute)} \rightarrow$
2. B
   $\text{Cu} + 4\text{HNO}_3\text{ (conc.)} \rightarrow$
3. C
   $4\text{Zn} + 10\text{HNO}_3\text{ (dilute)} \rightarrow$
4. D
   $\text{Zn} + 4\text{HNO}_3\text{ (conc.)} \rightarrow$

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1. A
   Hydrochloric acid
2. B
   Nitric acid
3. C
   Sulphuric acid
4. D
   Phosphoric acid

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1. A
   All carbons in diamond are linked by carbon-carbon single bond.
2. B
   Graphite is layered structure in which layers are held together by weak van der Waals forces.
3. C
   Graphite layers are formed by hexagonal rings of carbon atoms.
4. D
   Graphite layers are held together by carbon-carbon single bond.

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1. A
   Solid carbon dioxide
2. B
   Liquid carbon dioxide
3. C
   Liquid nitrogen
4. D
   Liquid ammonia

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1. A
   pancreatic juice
2. B
   duodenal secretion
3. C
   large intestine secretion
4. D
   bile juice

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1. A
   left auricle
2. B
   left ventricle
3. C
   right auricle
4. D
   right ventricle

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1. A
   water
2. B
   carbon dioxide
3. C
   oxygen
4. D
   light

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1. A
   Effector—sensory neuron—spinal cord—motor neuron—receptor
2. B
   Receptor—sensory neuron—spinal cord—motor neuron—effector
3. C
   Receptor—sensory neuron—brain—motor neuron—effector
4. D
   Sensory neuron—receptor—brain—effector—motor neuron

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1. A
   $N$ and $2N$
2. B
   $2N$ and $2N$
3. C
   $N$ and $3N$
4. D
   $2N$ and $3N$

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1. A
   $\frac{2}{5}R$
2. B
   $\frac{3}{5}R$
3. C
   $\frac{3}{2}R$
4. D
   $4R$

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1. A
   $0$ °C
2. B
   $-100$ °C
3. C
   $-273\cdot15$ °C
4. D
   $-173\cdot15$ °C

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1. A
   1, 2 and 3
2. B
   1 and 2 only
3. C
   2 and 3 only
4. D
   1 only

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1. A
   $T$
2. B
   $2T$
3. C
   $4T$
4. D
   $T/2$

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1. A
   Red—live wire, Green—neutral wire, Black—ground wire
2. B
   Red—neutral wire, Green—ground wire, Black—live wire
3. C
   Red—live wire, Green—ground wire, Black—neutral wire
4. D
   Red—ground wire, Green—live wire, Black—neutral wire

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1. A
   $R_1 > R_2 > R_3$
2. B
   $R_1 < R_3 < R_2$
3. C
   $R_3 < R_1 < R_2$
4. D
   $R_3 > R_2 > R_1$

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1. A
   1 and 3 only
2. B
   1 and 4
3. C
   2, 3 and 4
4. D
   1, 2 and 3

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1. A
   $g_1$
2. B
   $2g_1$
3. C
   $g_1/2$
4. D
   $g_1/4$

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

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

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1. A
   Jamuna
2. B
   Padma
3. C
   Ganga
4. D
   Brahmaputra

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1. A
   Manipur
2. B
   Mizoram
3. C
   Tripura
4. D
   Nagaland

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1. A
   Cirrocumulus
2. B
   Cumulus
3. C
   Nimbostratus
4. D
   Cumulonimbus

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