Free OAT Exam Questions That Helps Candidates Pass

Comprehensive and Detailed Explanation (150–250 words):

Neon is a noble gas in Group 18. Oxygen (A), nitrogen (C), and fluorine (D) are reactive nonmetals. Noble gases are chemically inert. Correct: B.

Comprehensive and Detailed Explanation (150–250 words):

Ohm’s law: I=V/R=12/6=2I = V/R = 12/6 = 2 A. Option B is correct. Option A underestimates, while C and D are too high. This illustrates the direct proportionality between current and voltage, and inverse relationship with resistance.

Comprehensive and Detailed Explanation (150–250 words):

Use the thin lens equation 1f=1do+1di\frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i}. With f=+10 cmf = +10\,\text{cm} and do=30 cmd_o = 30\,\text{cm}: 1/di=1/10−1/30=(3−1)/30=2/30=1/151/d_i = 1/10 - 1/30 = (3 - 1)/30 = 2/30 = 1/15, so di=+15 cmd_i = +15\,\text{cm}. Positive image distance indicates a real image on the side opposite the object. The transverse magnification is m=−di/do=−15/30=−0.5m = -d_i/d_o = -15/30 = -0.5; the negative sign denotes inversion and the magnitude indicates the image is half the object’s size. Option B incorrectly claims an upright real image (real images from single converging lenses are inverted for objects outside the focal length) and wrong magnification. Options C and D describe virtual images (negative did_i) that would occur only if the object were inside the focal length (do

Comprehensive and Detailed Explanation (150–250 words):

The de Broglie wavelength is given by λ=h/p\lambda = h / p, where p=mvp = mv. Here, m=9.11×10−31 kgm = 9.11 \times 10^{-31}\,\text{kg} and v=2.0×106 m/sv = 2.0 \times 10^6\,\text{m/s}. Thus, p=9.11×10−31×2.0×106=1.822×10−24 kg\cdotpm/sp = 9.11 \times 10^{-31} \times 2.0 \times 10^6 = 1.822 \times 10^{-24}\,\text{kg·m/s}. Then λ=6.63×10−34/1.822×10−24≈3.64×10−10 m\lambda = 6.63 \times 10^{-34} / 1.822 \times 10^{-24} \approx 3.64 \times 10^{-10}\,\text{m}. This is in the X-ray region of the spectrum. Option B (5.46 × 10⁻¹⁰ m) or D (6.63 × 10⁻¹⁰ m) arise from calculation mistakes in numerator or denominator. Option C (1.82 × 10⁻¹⁰ m) corresponds to halving the correct wavelength, possibly due to doubling the momentum erroneously. The correct answer is A.

Comprehensive and Detailed Explanation (150–250 words):

Facilitated diffusion uses carrier proteins or channels to move substances down a concentration gradient without ATP. The sodium-potassium pump (A) and vesicle-mediated transport (B, D) require energy → active transport. Correct: C.