CBSE Class 12 Physics 2026 question paper (55/4)

1. A.
   $\frac{1}{2}(\rho_1 + \rho_2)$
2. B.
   $\rho_1 + \rho_2$
3. C.
   $\sqrt{\rho_1 \rho_2}$
4. D.
   $2\,(\rho_1 + \rho_2)$

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1. A.
   $\frac{m_1}{m_2} > \frac{q_1}{q_2}$
2. B.
   $\frac{m_1}{m_2} > \frac{q_2}{q_1}$
3. C.
   $\frac{m_1}{m_2} < \frac{q_1}{q_2}$
4. D.
   $\frac{m_1}{m_2} < \frac{q_2}{q_1}$

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1. A.
   $\frac{e}{n}$
2. B.
   $ne$
3. C.
   $\frac{ne}{r}$
4. D.
   $\frac{e}{nr}$

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1. A.
   $[\mathrm{M\,L\,T^{-3}\,A}]$
2. B.
   $[\mathrm{M\,L^{2}\,T^{-3}\,A^{-1}}]$
3. C.
   $[\mathrm{M\,L^{2}\,T^{-2}\,A^{-1}}]$
4. D.
   $[\mathrm{M\,L^{2}\,T^{-3}\,A^{-2}}]$

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1. A.
   $-\,\hat{i}$
2. B.
   $-\,\hat{j}$
3. C.
   $\hat{k}$
4. D.
   $\hat{j}$

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1. A.
   14 and 7
2. B.
   10 and 14
3. C.
   0 and 10
4. D.
   10 and 0

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1. A.
   $3 \times 10^{8}\ \mathrm{ms^{-1}}$
2. B.
   $2 \times 10^{8}\ \mathrm{ms^{-1}}$
3. C.
   $3{\cdot}3 \times 10^{-9}\ \mathrm{ms^{-1}}$
4. D.
   $5 \times 10^{-9}\ \mathrm{ms^{-1}}$

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1. A.
   cut-off potential will decrease.
2. B.
   cut-off potential will increase.
3. C.
   saturation current will decrease.
4. D.
   saturation current will increase.

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1. A.
   Only Na and K show photoelectric emission.
2. B.
   Only Mo will not show photoelectric emission.
3. C.
   All of the given metals show photoelectric emission.
4. D.
   None of them show photoelectric emission.

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1. A.
   increase by 100% of its initial value.
2. B.
   increase by 50% of its initial value.
3. C.
   decrease by 25% of its initial value.
4. D.
   decrease by 50% of its initial value.

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1. A.
   infrared region
2. B.
   ultraviolet region
3. C.
   visible region
4. D.
   partly in ultraviolet region and partly in visible region

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1. A.
   p-region only
2. B.
   n-region only
3. C.
   depletion region
4. D.
   the diode

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   A straight line through the origin over the whole range of V.
2. B.
   A curve rising steeply from the origin which then flattens and turns slightly downward at large V.
3. C.
   A line straight near the origin which then bends away below its own dashed straight-line extension.
4. D.
   A line straight near the origin which then bends away above its own dashed straight-line extension.

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1. A.
   due to error in voltmeter reading only.
2. B.
   due to error in ammeter reading only.
3. C.
   equal to the sum of error in voltmeter reading and error in ammeter reading.
4. D.
   equal to error in voltmeter reading divided by the error in ammeter reading.

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1. A.
   reading in ammeter decreases and reading in voltmeter increases.
2. B.
   readings in both voltmeter and ammeter increase.
3. C.
   reading in ammeter increases and reading in voltmeter decreases.
4. D.
   readings in both voltmeter and ammeter decrease.

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1. A.
   $v_1 > v_2 > v_3$
2. B.
   $v_2 > v_3 > v_1$
3. C.
   $v_3 > v_2 > v_1$
4. D.
   $v_1 = v_2 = v_3$

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1. A.
   $E_1 = E_2 = E_3$
2. B.
   $E_3 > E_2 > E_1$
3. C.
   $E_2 > E_3 > E_1$
4. D.
   $E_1 > E_2 > E_3$

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1. A.
   virtual, real
2. B.
   real, virtual
3. C.
   virtual, virtual
4. D.
   real, real

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1. A.
   colour of light
2. B.
   focal length of objective lens
3. C.
   focal length of eyepiece
4. D.
   apertures of objective lens and eyepiece

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1. A.
   The focal length of objective lens $(f_o)$ is larger than the focal length of eyepiece $(f_e)$.
2. B.
   Its magnifying power can be increased by increasing the focal length of objective lens $(f_o)$.
3. C.
   The distance between two lenses is more than $(f_o + f_e)$.
4. D.
   The magnifying power can be decreased by increasing the focal length of eyepiece.

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1. A.
   84 cm
2. B.
   76 cm
3. C.
   20 cm
4. D.
   320 cm

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1. A.
   320
2. B.
   84
3. C.
   76
4. D.
   20

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1. A.
   100%
2. B.
   200%
3. C.
   300%
4. D.
   400%

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

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1. A.
   Drift velocity only
2. B.
   Thermal velocity only
3. C.
   Both drift velocity and thermal velocity
4. D.
   Neither drift nor thermal velocity

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1. A.
   $\frac{m_1}{m_2} > \frac{q_1}{q_2}$
2. B.
   $\frac{m_1}{m_2} > \frac{q_2}{q_1}$
3. C.
   $\frac{m_1}{m_2} < \frac{q_1}{q_2}$
4. D.
   $\frac{m_1}{m_2} < \frac{q_2}{q_1}$

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1. A.
   infrared region
2. B.
   ultraviolet region
3. C.
   visible region
4. D.
   partly in ultraviolet region and partly in visible region

Tap an option to check your answer.

1. A.
   increase by 100% of its initial value.
2. B.
   increase by 50% of its initial value.
3. C.
   decrease by 25% of its initial value.
4. D.
   decrease by 50% of its initial value.

Tap an option to check your answer.

1. A.
   p-region only
2. B.
   n-region only
3. C.
   depletion region
4. D.
   the diode

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1. A.
   $6 \times 10^{-4}\ \mathrm{Am^2}$
2. B.
   $3 \times 10^{-5}\ \mathrm{Am^2}$
3. C.
   $1{\cdot}5 \times 10^{-4}\ \mathrm{Am^2}$
4. D.
   $5 \times 10^{-5}\ \mathrm{Am^2}$

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1. A.
   14 and 7
2. B.
   10 and 14
3. C.
   0 and 10
4. D.
   10 and 0

Tap an option to check your answer.

1. A.
   $3 \times 10^{8}\ \mathrm{ms^{-1}}$
2. B.
   $2 \times 10^{8}\ \mathrm{ms^{-1}}$
3. C.
   $3{\cdot}3 \times 10^{-9}\ \mathrm{ms^{-1}}$
4. D.
   $5 \times 10^{-9}\ \mathrm{ms^{-1}}$

Tap an option to check your answer.

1. A.
   Only Na and K show photoelectric emission.
2. B.
   Only Mo will not show photoelectric emission.
3. C.
   All of the given metals show photoelectric emission.
4. D.
   None of them show photoelectric emission.

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1. A.
   cut-off potential will increase.
2. B.
   maximum kinetic energy of photoelectrons will remain the same.
3. C.
   photocurrent will increase.
4. D.
   cut-off potential will decrease.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

Tap an option to check your answer.

1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   virtual, real
2. B.
   real, virtual
3. C.
   virtual, virtual
4. D.
   real, real

Tap an option to check your answer.

1. A.
   colour of light
2. B.
   focal length of objective lens
3. C.
   focal length of eyepiece
4. D.
   apertures of objective lens and eyepiece

Tap an option to check your answer.

1. A.
   The focal length of objective lens $(f_o)$ is larger than the focal length of eyepiece $(f_e)$.
2. B.
   Its magnifying power can be increased by increasing the focal length of objective lens $(f_o)$.
3. C.
   The distance between two lenses is more than $(f_o + f_e)$.
4. D.
   The magnifying power can be decreased by increasing the focal length of eyepiece.

Tap an option to check your answer.

1. A.
   84 cm
2. B.
   76 cm
3. C.
   20 cm
4. D.
   320 cm

Tap an option to check your answer.

1. A.
   320
2. B.
   84
3. C.
   76
4. D.
   20

Tap an option to check your answer.

1. A.
   A straight line through the origin over the whole range of V.
2. B.
   A curve rising steeply from the origin which then flattens and turns slightly downward at large V.
3. C.
   A line straight near the origin which then bends away below its own dashed straight-line extension.
4. D.
   A line straight near the origin which then bends away above its own dashed straight-line extension.

Tap an option to check your answer.

1. A.
   due to error in voltmeter reading only.
2. B.
   due to error in ammeter reading only.
3. C.
   equal to the sum of error in voltmeter reading and error in ammeter reading.
4. D.
   equal to error in voltmeter reading divided by the error in ammeter reading.

Tap an option to check your answer.

1. A.
   reading in ammeter decreases and reading in voltmeter increases.
2. B.
   readings in both voltmeter and ammeter increase.
3. C.
   reading in ammeter increases and reading in voltmeter decreases.
4. D.
   readings in both voltmeter and ammeter decrease.

Tap an option to check your answer.

1. A.
   $v_1 > v_2 > v_3$
2. B.
   $v_2 > v_3 > v_1$
3. C.
   $v_3 > v_2 > v_1$
4. D.
   $v_1 = v_2 = v_3$

Tap an option to check your answer.

1. A.
   $E_1 = E_2 = E_3$
2. B.
   $E_3 > E_2 > E_1$
3. C.
   $E_2 > E_3 > E_1$
4. D.
   $E_1 > E_2 > E_3$

Tap an option to check your answer.

1. A.
   Only Na and K show photoelectric emission.
2. B.
   Only Mo will not show photoelectric emission.
3. C.
   All of the given metals show photoelectric emission.
4. D.
   None of them show photoelectric emission.

Tap an option to check your answer.

1. A.
   $3 \times 10^{8}\ \mathrm{ms^{-1}}$
2. B.
   $2 \times 10^{8}\ \mathrm{ms^{-1}}$
3. C.
   $3{\cdot}3 \times 10^{-9}\ \mathrm{ms^{-1}}$
4. D.
   $5 \times 10^{-9}\ \mathrm{ms^{-1}}$

Tap an option to check your answer.

1. A.
   14 and 7
2. B.
   10 and 14
3. C.
   0 and 10
4. D.
   10 and 0

Tap an option to check your answer.

1. A.
   p-region only
2. B.
   n-region only
3. C.
   depletion region
4. D.
   the diode

Tap an option to check your answer.

1. A.
   $\frac{m_1}{m_2} > \frac{q_1}{q_2}$
2. B.
   $\frac{m_1}{m_2} > \frac{q_2}{q_1}$
3. C.
   $\frac{m_1}{m_2} < \frac{q_1}{q_2}$
4. D.
   $\frac{m_1}{m_2} < \frac{q_2}{q_1}$

Tap an option to check your answer.

1. A.
   infrared region
2. B.
   ultraviolet region
3. C.
   visible region
4. D.
   partly in ultraviolet region and partly in visible region

Tap an option to check your answer.

1. A.
   increase by 100% of its initial value.
2. B.
   increase by 50% of its initial value.
3. C.
   decrease by 25% of its initial value.
4. D.
   decrease by 50% of its initial value.

Tap an option to check your answer.

1. A.
   only relaxation time '$\tau$' of electrons decreases with temperature.
2. B.
   only number of electrons per unit volume 'n' increases appreciably.
3. C.
   '$\tau$' decreases with temperature but 'n' does not change appreciably.
4. D.
   '$\tau$' decreases with temperature and 'n' increases.

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1. A.
   rate at which currents change in the two coils.
2. B.
   relative position and orientation of the coils.
3. C.
   currents in the two coils.
4. D.
   value of voltage induced in one coil due to change in value of current in the other coil.

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1. A.
   Mobility increases with increase in applied electric field.
2. B.
   Mobility decreases with increase in temperature.
3. C.
   Mobility is independent of the mass of the charge carrier.
4. D.
   Mobility increases with increase in temperature

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1. A.
   150 $\Omega$
2. B.
   125 $\Omega$
3. C.
   100 $\Omega$
4. D.
   75 $\Omega$

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

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1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

Tap an option to check your answer.

1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

Tap an option to check your answer.

1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

Tap an option to check your answer.

1. A.
   Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
2. B.
   Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
3. C.
   Assertion (A) is true, but Reason (R) is false.
4. D.
   Both Assertion (A) and Reason (R) are false.

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1. A.
   virtual, real
2. B.
   real, virtual
3. C.
   virtual, virtual
4. D.
   real, real

Tap an option to check your answer.

1. A.
   colour of light
2. B.
   focal length of objective lens
3. C.
   focal length of eyepiece
4. D.
   apertures of objective lens and eyepiece

Tap an option to check your answer.

1. A.
   The focal length of objective lens $(f_o)$ is larger than the focal length of eyepiece $(f_e)$.
2. B.
   Its magnifying power can be increased by increasing the focal length of objective lens $(f_o)$.
3. C.
   The distance between two lenses is more than $(f_o + f_e)$.
4. D.
   The magnifying power can be decreased by increasing the focal length of eyepiece.

Tap an option to check your answer.

1. A.
   84 cm
2. B.
   76 cm
3. C.
   20 cm
4. D.
   320 cm

Tap an option to check your answer.

1. A.
   320
2. B.
   84
3. C.
   76
4. D.
   20

Tap an option to check your answer.

1. A.
   A straight line through the origin over the whole range of V.
2. B.
   A curve rising steeply from the origin which then flattens and turns slightly downward at large V.
3. C.
   A line straight near the origin which then bends away below its own dashed straight-line extension.
4. D.
   A line straight near the origin which then bends away above its own dashed straight-line extension.

Tap an option to check your answer.

1. A.
   due to error in voltmeter reading only.
2. B.
   due to error in ammeter reading only.
3. C.
   equal to the sum of error in voltmeter reading and error in ammeter reading.
4. D.
   equal to error in voltmeter reading divided by the error in ammeter reading.

Tap an option to check your answer.

1. A.
   reading in ammeter decreases and reading in voltmeter increases.
2. B.
   readings in both voltmeter and ammeter increase.
3. C.
   reading in ammeter increases and reading in voltmeter decreases.
4. D.
   readings in both voltmeter and ammeter decrease.

Tap an option to check your answer.

1. A.
   $v_1 > v_2 > v_3$
2. B.
   $v_2 > v_3 > v_1$
3. C.
   $v_3 > v_2 > v_1$
4. D.
   $v_1 = v_2 = v_3$

Tap an option to check your answer.

1. A.
   $E_1 = E_2 = E_3$
2. B.
   $E_3 > E_2 > E_1$
3. C.
   $E_2 > E_3 > E_1$
4. D.
   $E_1 > E_2 > E_3$

Tap an option to check your answer.