Assertion-Reason Type Question

Assertion (A): The magnetic field at the center of a circular current carrying loop is directly proportional to the current flowing through it.

Reason (R): According to Biot-Savart's law, magnetic field produced by a current element is proportional to the current element.

Choose the correct answer from the options given below:

• (A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• (B) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• (C) Assertion is true but Reason is false.
• (D) Assertion is false but Reason is true.

Match the following electromagnetic waves with their correct energy order.

{Column I} & {Column II}

(A) Gamma rays & (I) Lowest frequency

(B) X-rays & (II) Highest energy

(C) Microwaves & (III) Used in radar communication

(D) Radio waves & (IV) Used in medical imaging

Choose the correct answer from the options given below:

• (A) A-II, B-IV, C-III, D-I
• (B) A-IV, B-II, C-I, D-III
• (C) A-II, B-I, C-IV, D-III
• (D) A-III, B-IV, C-II, D-I

The ratio of de Broglie wavelength of an electron to that of a proton moving with the same kinetic energy is:

• (A) \(\sqrt{\frac{m_p}{m_e}}\)
• (B) \(\frac{m_p}{m_e}\)
• (C) \(\sqrt{\frac{m_e}{m_p}}\)
• (D) 1

A proton and an alpha particle are accelerated through the same potential difference. The ratio of their kinetic energies will be:

• (A) 1 : 1
• (B) 1 : 2
• (C) 2 : 1
• (D) 4 : 1

Assertion-Reason Type Question

Assertion (A): Torque acting on a current loop in a magnetic field is maximum when the plane of the loop is parallel to the magnetic field.

Reason (R): Torque on a magnetic dipole is given by: \(\tau = MB \sin\theta\) where \(\theta\) is the angle between magnetic moment and magnetic field.

Choose the correct answer from the options given below:

• (A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• (B) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• (C) Assertion is true but Reason is false.
• (D) Assertion is false but Reason is true.

The focal length of a concave mirror is 20 cm. If the object is placed at 30 cm from the mirror, the image distance will be:

• (A) 60 cm
• (B) 30 cm
• (C) 12 cm
• (D) 24 cm

The magnifying power of a simple microscope increases when:

• (A) Focal length increases
• (B) Focal length decreases
• (C) Aperture decreases
• (D) Radius of lens increases

Match the following quantities with their SI units.

{Column I} & {Column II}

(A) Magnetic flux & (I) Tesla

(B) Magnetic field & (II) Weber

(C) Capacitance & (III) Farad

(D) Resistance & (IV) Ohm

Choose the correct answer from the options given below:

• (A) A-II, B-I, C-III, D-IV
• (B) A-I, B-II, C-IV, D-III
• (C) A-III, B-II, C-I, D-IV
• (D) A-IV, B-III, C-II, D-I

A photon has energy 6 eV. Its frequency is approximately:

• (A) \(1.45 \times 10^{15}\) Hz
• (B) \(6 \times 10^{15}\) Hz
• (C) \(9 \times 10^{14}\) Hz
• (D) \(3 \times 10^{8}\) Hz

Assertion-Reason Type Question

Assertion (A): In photoelectric effect, stopping potential depends upon frequency of incident radiation.

Reason (R): Maximum kinetic energy of emitted electrons increases with frequency.

Choose the correct answer from the options given below:

• (A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• (B) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
• (C) Assertion is true but Reason is false.
• (D) Assertion is false but Reason is true.